Leaders in the US and Europe remain on high alert over a possible Russian invasion of Ukraine. They have been trying to agree on the best way to respond -- with diplomacy, with sanctions, or with military action of their own. They have been saying for months that they want a peaceful solution. But US President Joe Biden now says he is convinced that the Russian leader has made his decision.

Biden made the remarks at a press conference in Washington on Friday.

He said the US has reason to believe the Russian forces are planning to and intend to attack Ukraine in the coming days.

He said that any attack will be met with a united response, and that the US and its allies are prepared to defend every inch of NATO territory from any threat to their collective security.

Biden made his remarks just after speaking with leaders in Europe, Canada, NATO, and the European Union.

He disputed Moscow's claims that its troops have begun withdrawing from the Ukrainian border. He says just the opposite is true -- that the force has grown, from 100,000 to "well over 150,000" soldiers. Russian-backed separatists in Eastern Ukraine have also ordered people there to evacuate to Russian territory.

Biden and EU leaders are trying to reassure their allies in the region. They have been sending extra troops and equipment to bases in the area. They say they are still committed to diplomacy. However, Biden has said he has no plans for direct talks with Putin anytime soon.