We use your sign-up to provide content in ways that you've consented to and improve our understanding of you. This may include advertisements from us and 3rd parties based on our understanding. Boris Johnson, 57, and Joe Biden, 79, were joined by French President Emmanuel Macron, 43, Italy's prime minister Mario Draghi, 74, and the outgoing German Chancellor Angela Merkel, 67.
The US President said that he had pledged his unwavering support for Ukraine against Moscow and warned Vladimir Putin, 69, that America could impose sanctions on Russia if it crosses the border.
Some 70,000 troops are believed to have been mobilised on the Russian-Ukraine border.
Ukrainian president Volodymyr Zelensky, 43, said on Monday Kyiv's forces were capable of fending off a Russian onslaught during a military display day of US armoured vehicles and patrol boats.
He said that the servicemen of the Armed Forces of Ukraine continue to fulfill their most important mission - to defend the freedom and sovereignty of the state from Russian aggressors.