12:32,

YEREVAN, FEBRUARY 11, ARMENPRESS. US President Joe Biden has called on all American citizens remaining in Ukraine to leave the country immediately, citing increased threats of Russian military action, BBC reports.

Mr Biden said he would not send troops to rescue Americans if a military clash happens.

He warned that "things could go crazy quickly" in the region.

UK Prime Minister Boris Johnson said on Thursday that Europe faced its biggest security crisis in decades amid the tensions.

The US State Department urged Americans in Ukraine to leave immediately.

“American citizens should leave now”, Mr Biden told NBC News.

“We're dealing with one of the largest armies in the world. It's a very different situation and things could go crazy quickly”.