Both the vessels are on a list of ships subject to sanctions imposed against Russia following its full-scale invasion of Ukraine.

Russian President Vladimir Putin said that a US plan to end the war in Ukraine could “form the basis for future agreements” but renewed threats to seize more territory by force unless Kyiv withdraws.

Russian forces strafed Ukraine’s capital with a major missile barrage overnight, killing at least three people and causing widespread power outages, as the US ramps up pressure on President Volodymyr Zelenskiy to agree to concessions in the almost four-year-old war.

"None of us really know what Zelenskyy is like operating solo, because he never has," one expert told NBC News.

Ukraine's gas facilities have suffered severe damage from Russian drone and missile attacks, forcing the country to import more gas

After working together during the successful presidential campaign of 2019, Yermak became Zelensky's chief of staff. He stood next to the president as he gave his now famous "we are still here" speech as the Russians descended on Kyiv at the start of their full-scale invasion in February 2022.

President Volodymyr Zelenskiy's powerful chief of staff Andriy Yermak, a close ally who has headed Ukraine's negotiation team at fraught U.S.-backed peace talks, quit on Friday, hours after anti-corruption agents searched his home.

Ukraine has agreed to an updated US-brokered peace deal as Russia launches attacks on Ukraine's energy grid