Talks between U.S. President Donald Trump and Russian leader Vladimir Putin produced enough movement to justify a meeting with Ukrainian and European leaders, U.S. Secretary of State Marco Rubio told CBS on Sunday.

Ukraine can count on US participation in a security pledge similar to NATO's mutual defence commitment, European Commission President Ursula von der Leyen said on Sunday at a press briefing with the Ukrainian president.

President Donald Trump supports Russian leader Vladimir Putin's proposal for Moscow to take full control of the Donbas and freeze the front lines elsewhere for a deal with Ukraine.

The US president demanded a ceasefire before he met Putin. His change of mind flies in the face of what Europe and Ukraine want.

President Donald Trump supports Russian leader Vladimir Putin's proposal for Moscow to take full control of the Donbas and freeze the front lines elsewhere for a deal with Ukraine.

After meeting the Russian president, President Trump told European leaders he now favors giving up territory Ukraine controls to Russia to end the fighting, a concession Ukraine has long opposed.

President Trump told European leaders in a phone call from Air Force One that he is more willing than before for the U.S. to provide direct security guarantees to Ukraine, according to people familiar with the content of the conversation.