'Things could get crazy quickly': Joe Biden tells Americans in Ukraine to leave 'now'

Joe Biden has repeated his stark warning that any Americans still in Ukraine should leave as soon as possible, amid fears of an impending Russian invasion of the eastern European country. “It’s not like we’re dealing with a terrorist organisation. We’re dealing with one of the largest armies in the world. It’s a very different situation, and things could go crazy quickly,” he told NBC.

When asked what scenario could prompt him to send troops to rescue Americans fleeing the country. Mr Biden responded: “There’s not. That's a world war when Americans and Russia start shooting at one another.”

Amid a deadlock between Russia and Nato, President Putin's forces held sweeping maneuvers north of Ukraine in Belarus, part of a buildup of more than 130,000 troops on the borders which has stoked Western fears of an invasion. Nato also has stepped up military deployments to bolster its eastern flank, with the US sending troops to Poland and Romania.

A British Royal Air Force jet carrying 350 troops landed on Thursday in Poland - a move that followed London sending anti-tank missiles to Ukraine to help boost its defenses.

He argued that if Mr Putin is “foolish enough to go in, he’s smart enough not to, in fact, do anything that would negatively impact on American citizens".

ITV News Correspondent Rachel Younger is in Moscow, finding out what Russians think about the rising tensions against Ukraine

Asked whether he’s ever said that to Mr Putin, Mr Biden said he had. “I didn’t have to tell him that. I’ve spoken about that. He knows that,” Mr Biden said. For weeks, the state department has advised Americans in Ukraine to leave the country.

Speaking in Moscow, Mr Putin said Russia was continuing a series of talks with the US and its allies and is working on a reply to Western security proposals. Nato Secretary-General Jens Stoltenberg said he sent a letter to Russian foreign minister Sergey Lavrov repeating an invitation to a series of talks on improving European security.

Listen to ITV News' podcast - Shamima Begum: The Blame Game - as we chart her journey into ISIS territory and her escape from it.