US President Donald Trump

US President Donald Trump has cancelled a meeting with Russian President Vladimir Putin that was due to take place this weekend at the G20 summit in Argentina.

"Based on the fact that the ships and sailors have not been returned to Ukraine from Russia, I have decided it would be best for all parties concerned to cancel my previously scheduled meeting... in Argentina with President Vladimir Putin," Trump said on Twitter.

"I look forward to a meaningful Summit again as soon as this situation is resolved!" he added, posting just after he left Washington for Buenos Aires. He had earlier indicated he would make a final decision on the meeting during his flight after receiving a briefing.

On Sunday, Russia seized three Ukrainian naval vessels off the Crimea Peninsula, a territory it annexed from Ukraine in 2014. The Russian coastguard opened fire and captured the Ukrainian naval vessels in the Kerch Strait, which links the Sea of Azov and the Black Sea.