US president Donald Trump has failed to secure a ceasefire in Ukraine from Russian president Vladimir Putin, and appeared to back down from a threat to impose new sanctions on Moscow after their summit in Alaska made no obvious progress towards ending the war.

After leaving Alaska, Trump says he would prefer to "go directly to a peace agreement" to end the war in Ukraine as he prepares to meet Zelensky on Monday.

For Russia, the results of the Alaska summit between President Donald Trump and Russian President Vladimir Putin marked a turning point in relations with the United States, underlined by Trump subsequently abandoning demands for a halt in fighting in Ukraine.