Ukrainian President Volodymyr Zelenskiy on Friday said in a tweet that he was grateful to US President Joe Biden for Washington's "unprecedented" diplomatic and military assistance.
Separately Ukrainian Foreign Minister Dmytro Kuleba said he had spoken to US Secretary of State Antony Blinken about this week's talks with Russia, after Russia massed tens of thousands of troops near Ukraine's borders.
"Good to know that diplomatic track of contacts with Russia remains active," Kuleba said in a tweet.