This has been CNBC's live blog tracking developments on the war in Ukraine on Oct.18, 2023.

Russian President Vladimir Putin said Washington's decision to supply long-range missiles to Ukraine was "a mistake." His comments came during a news conference at China's Belt and Road Initiative forum in Beijing.

The Kremlin leader said it was an error to have become "more and more personally drawn into" the conflict after Ukrainian President Volodymyr Zelenskyy said Tuesday that Kyiv had fired the first U.S.-supplied, long-range ATACMS missile.

During Putin's visit, Chinese President Xi Jinping is reported to have praised the ties between Beijing and Moscow as the pair look to strengthen their "no limits" partnership.

In Ukraine, lethal airstrikes killed civilians in the city of Zaporizhzhia overnight.

Russia and Ukraine blamed each other for the casualties in Zaporizhzhia. Ukrainian officials attributed blame to "racist terrorist forces," while a Moscow-installed Russian official in the city said the destruction came as result of "clumsy actions" by the Ukrainian armed forces.

Russia and the United Arab Emirates are reportedly set to meet with the U.N. Security Council Wednesday to discuss the Israel-Hamas war.

At least seven killed in Russian strikes, Ukrainian officials say

Russian strikes killed at least seven civilians overnight and on Wednesday, according to updates from Ukrainian officials. The death toll was previously announced as lower.

CNBC has not independently verified the reports.

The deputy mayor of the southeastern city of Zaporizhzhia said on Telegram that four people were killed overnight, as two more bodies were found during search and rescue operations.

A Moscow-installed official in part of the region controlled by Russia blamed the strikes on Ukraine.

Two deaths were reported by an official in Kherson, and one was reported in the Dnipropetrovsk region.

— Jenni Reid

Ukraine condemns Russian bill to revoke nuclear test ban treaty

Ukraine released a statement Wednesday condemning Russia's moves to withdraw from a global nuclear test ban treaty.

A law to revoke Russia's ratification of the treaty passed through the Duma, Russia's lower house of parliament, earlier in the day.

"The world is witnessing another provocative step of the aggressor state, aimed at increasing nuclear blackmail," Ukraine's Ministry of Foreign Affairs said in a statement, according to a Google translation.

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) "remains one of the key legal elements of the global security architecture in the area of ​​nuclear arms limitation and nuclear non-proliferation," the statement said.

"Ukraine condemns Russia's steps to withdraw ratification of the Treaty and calls on the international community to respond accordingly to Moscow's provocations aimed at harming the object and purpose of the CTBT."

The treaty was adopted by the United Nations General Assembly in 1996, though eight nations have not ratified it, including the United States.

— Jenni Reid

Putin says U.S. supplying long-range missiles to Ukraine is 'a mistake'

Russian President Vladimir Putin said the U.S. deciding to supply Ukraine with long-range missiles was "a mistake," in a news conference in Beijing, as reported by Reuters.

"Firstly, this of course causes harm and creates an additional threat. Secondly, we will of course be able to repel these attacks. War is war," Putin said.

"But most importantly, it fundamentally lacks the capacity to change the situation on the line of contact at all ... This is another mistake by the United States," he added.

Ukrainian President Volodymyr Zelenskyy said Tuesday that Ukraine had fired the first U.S.-supplied, long-range ATACMS missiles in a nightly address. Zelenskyy had repeatedly asked Washington for the weapons to help in its offensive.

Putin also criticized U.S. involvement in the war more widely.

"A mistake of a larger scale, as yet invisible but still of great importance, is that the United States is becoming more and more personally drawn into this conflict. And let no one say that they have nothing to do with this. We believe they do," Putin said.

— Hannah Ward-Glenton

Putin's 'nuclear briefcase' caught on camera, media reports say

Russian President Vladimir Putin has been captured on camera with his so-called "nuclear briefcase," Reuters news agency reported.

The briefcase, which can allegedly be used to order a nuclear strike, is said to never stray far from Putin's side and is rarely filmed.

The footage shows the Russian leader walking between meetings, the report says, ahead of an entourage of naval officers.

"There are certain suitcases without which no trip of Putin's is complete," the Kremlin correspondents of state news agency RIA said in a post on Telegram under the footage, as reported by Reuters.

— Hannah Ward-Glenton

Putin and Xi 'exchanged views' on Israel-Hamas conflict, state media reports

Russian President Vladimir Putin and his Chinese counterpart Xi Jinping had an "in-depth exchange of views" on the Israel-Hamas conflict, Chinese state media outlet Xinhua reported, according to a Google translation.

The two leaders met during Putin's closely-watched trip to Beijing for the third Belt and Road Forum. The pair also discussed the "no limits" partnership between their two countries during the meeting.

Xi said that "China supports the Russian people in pursuing the path of national rejuvenation independently and safeguarding national sovereignty, security and development interests," Xinhua reports.

The Chinese president said that both sides should promote the high-quality development of China-Russia cooperation and "actively explore cooperation in strategic emerging industries."

— Hannah Ward-Glenton

Ukraine strikes Russian field camps in Kursk region

Ukrainian forces launched at least 18 drone strikes on Russian field camps in the Kursk region of Russia, Ukrainian security service sources reportedly told the Kyiv Post and Ukrinform.

The drones hit military field camps near the village of Postoyalye Dvory, which is around 110 kilometers (68 miles) from the Ukrainian border, the Post reported.

Up to 3,000 Russian soldiers and approximately 80 units of military equipment are stationed in the area, according to the reports.

The Russian Defense Ministry did not immediately respond to CNBC's request for comment.

— Hannah Ward-Glenton

Russian lower house passes law to scrap ban on nuclear testing

A law to revoke Russia's ratification of the global nuclear test ban treaty completed its passage through the Duma, Russia's lower house of parliament, Wednesday.

Deputies passed the second and third readings of the bill with unanimous votes in favor.

"We rarely have great consolidation at all, and in this regard, our vote will be a response to the United States of America for its boorish attitude towards its responsibilities to maintain global security," Vyacheslav Volodin, the State Duma chairman, said Tuesday.

The U.S. signed but never ratified the 1996 Comprehensive Test Ban Treaty.

— Hannah Ward-Glenton

Russian forces 'unlikely' to make a breakthrough in northeast Ukraine, British defense ministry says

Russian ground forces on the Kupiansk-Lyman axis in northeast Ukraine are "highly unlikely" to achieve a major operational breakthrough, Britain's Defense Ministry said, thanks to Ukrainian forces retaining a "significant defensive presence."

The ministry delivered the update Wednesday via X, formerly known as Twitter.

While there has been "a significant increase in Russian offensive activity" in the area, there has been "limited success," the update said.

It's "highly likely" that the activity is part of an ongoing Russian offensive happening across multiple axes in eastern Ukraine, according to the report.

— Hannah Ward-Glenton

Putin to visit Vietnam 'soon,' Vietnamese state media reports

Russian President Vladimir Putin accepted an invitation from his Vietnamese counterpart to soon visit Vietnam as the two met on the sidelines of China's belt and Road Forum in Beijing, Vietnamese state media reported.

Vietnam remains one of Russia's closest partners in Asia, ties that were developed during the Soviet era, and Hanoi is a major buyer of Russian weapons.

Vietnam's President Vo Van Thuong invited Putin to "soon" visit the country and "Putin happily accepted the invitation," Vietnam News Agency, the state's official newswire, reported late on Tuesday.

— Reuters

Russian official: Gaza hospital attack is a criminal 'act of dehumanisation'

Russia's Foreign Ministry described a strike on a hospital in Gaza, in which hundreds of civilians were killed, as a dehumanizing crime, Reuters reported.

Foreign Ministry Spokesperson Maria Zakharova said Russia "qualif[ies] such a felonious deed as a crime, as an act of dehumanization," as she spoke to state-owned broadcaster Radio Sputnik.

At least 500 people were killed as a result of the Israeli strike on a hospital, AP reported.

The World Health Organization called for an investigation into Russian attacks on Ukrainian health facilities in May 2022.

— Hannah Ward-Glenton

Xi praises China-Russia ties in Putin meeting

Chinese President Xi Jinping praised China-Russia relations in talks with Russian President Vladimir Putin on Wednesday, state news outlet Xinhua reported.

"The political mutual trust between the two countries [is] continuously deepening," the article said.

"The two countries have maintained close and effective strategic coordination and bilateral trade volume has reached a historical high, which is progressing toward the goal of 200 billion U.S. dollars set by the two sides, Xi said."

Xi greeted Putin as he arrived in Beijing Tuesday for China's Belt and Road summit, before the Russian leader addressed a live audience Wednesday.

Speaking to 1,000 delegates representing over 130 countries, Putin said he agreed with Chinese President Xi Jinping that the Belt and Road idea "folds logically within multilateral efforts" to increase global cooperation.

— Hannah Ward-Glenton and Lee Ying Shan

Lethal airstrikes in Zaporizhzhia; Ukraine and Russia blame each other

At least two people were killed and two injured after an airstrike in Zaporizhzhia, Ukraine, according to reports from both sides.

Ukrainian officials blamed the Kremlin for the attack, while a Moscow-installed official in Russian-controlled parts of the city said Ukraine was responsible.

"Tonight, in the time period from 01:33 to 01:48, racist terrorist forces launched 6 rocket attacks on the territory of the city of Zaporizhia," head of the Zaporizhzhia Regional Military Administration, Yuriy Malashko, wrote on Telegram, according to a Google translation.

Eight apartments were damaged as a result of the attack and most of the residents were evacuated.

"As a result of the clumsy actions of the Ukrainian Armed Forces' air defense, a rocket hit an apartment building in the city center," Russian official Vladimir Rogov said on Telegram, according to a Google translation.

CNBC was unable to independently verify the reports.

— Hannah Ward-Glenton

Russia and UAE to meet UN Security Council, Russia reports

The United Arab Emirates and Russia have called for an emergency U.N. Security Council meeting on the situation in the Middle East, a Russian official wrote on Telegram.

"Russia and the UAE requested an urgent open meeting of the UN Security Council on the morning of October 18 in connection with the attack on a hospital in Gaza," said Russian deputy representative to the United Nations, Dmitry Polyansky, as translated by NBC News.

Russian news outlets suggest the meeting will happen at 5 p.m. Moscow time, which is 3 p.m. in London.

Both nations have been hedged as possible peace brokers in the Israel-Hamas conflict, with the UAE having signed a peace deal with Israel in 2020 and Russia traditionally treading a fine diplomatic line between Israel and its allies in the Middle East.

— Hannah Ward-Glenton

Ukraine fires U.S.-supplied long-range ATACMS missiles: Zelenskyy

Ukraine fired long-range ATACMS missiles for the first time after they were delivered by the U.S., Ukraine's Volodymyr Zelenskyy said in his nightly address Tuesday.

"Today, special thanks to the United States. Our agreements with President Biden are being implemented. They are executed very accurately, ATACMS have proven themselves," he said, according to a Google translation of a transcript.

Ukrainian politician Oleksiy Goncharenko posted on social media: "ATACMS is already with us. The airfield in Berdyansk with enemy equipment was hit by them. Thanks to our partners!"

The Wall Street Journal reported the news earlier Tuesday, citing people familiar with the matter.

A U.S. State Department spokesperson told CNBC it was unable to confirm the reports.

Ukraine has repeatedly said ATACMS are important to advance its difficult counteroffensive in Russian-occupied areas. The missiles can strike targets from as far away as about 180 miles.

However, U.S. officials previously said the U.S. does not have a large stockpile of excess ATACMS, while some have expressed fears use of the weapons could escalate the conflict.

— Jenni Reid

Biden plans to request $100 billion in funding that would include money for Israel, Ukraine

President Joe Biden is planning to submit a request for $100 billion in supplemental funding to Congress in the coming days that would include money for Israel, Taiwan, Ukraine and U.S. border security, two people familiar with the discussions told NBC News.

One source said the details of the package have not been finalized and could still change. The president is expected to send his request to lawmakers by the end of this week after he returns from his Middle East trip.

— NBC News

Russia's Putin upbeat on Power of Siberia 2 gas pipeline to China

Russian President Vladimir Putin told his Mongolian counterpart Ukhnaagiin Khurelsukh on Tuesday that he believed the Power of Siberia 2 pipeline project to bring Russian gas to China via Mongolia would move ahead at a "good pace".

Russia has increased energy supplies to China, the world's second-largest consumer of oil after the United States, as the west has imposed sweeping economic sanctions on Russia over its actions in Ukraine.

It already supplies natural gas to China via the Power of Siberia pipeline, and hopes to secure a major deal to bring another 50 billion cubic metres (bcm) a year via Power of Siberia 2. However, the talks have been long and painstaking as the key issues, such as the price of the gas, remain elusive.

"Everyone agrees with this project, all parties want to participate, want to work. It's a matter of implementation. I think we will move at a good pace," Putin told the Mongolian president in Beijing, where they were taking part in a conference on China's Belt and Road Initiative.

The Kremlin has said it does not expect any oil or gas deals to be clinched during Putin's visit and his meetings with Chinese leader Xi Jinping this week.

The Power of Siberia pipeline began supplying gas to China in late 2019.

It carried 10.5 bcm in 2021 and 15.5 bcm this year, and is due to supply 38 bcm a year by 2025, under a 30-year contract worth more than $400 billion.

— Reuters

Putin and Xi to discuss Israel-Hamas conflict, Kremlin spokesperson says

Russian President Vladimir Putin and his Chinese counterpart Xi Jinping will discuss the Israel-Hamas war during the former's visit to Beijing, Kremlin spokesperson Dmitry Peskov said, according to a Google-translated Telegram post by Tass news agency.

Peskov said Putin "has not yet come up with a peace initiative" on the conflict, and added that "Israel's ground operation in the Gaza Strip is fraught with dire consequences."

Russia's ability to intervene in the conflict is complex, Tatiana Stanovaya, senior fellow at the Carnegie Russia Eurasia Center and the founder of analysis firm R.Politik, said in an analysis note Oct. 9.

"On the one hand, Moscow might draw on its history of intra-Palestinian mediation and its ties with Hamas to gain a foothold in any peace process. It also sees the importance of its growing relationships with Iran and Arab states," she said.

Meanwhile, China said Israel's actions have "gone beyond self-defense" and that it "should heed the call of the international community and the Secretary-General of the United Nations to stop its collective punishment of the people in Gaza."

— Hannah Ward-Glenton and Holly Ellyatt