"We will not accept the campaign Russia is waging to subvert its democratic neighbors," Truss told Parliament, as reported in Reuters. "They have falsely cast Ukraine as a threat to justify their aggressive stance."

"The UK is working with our partners on these sanctions, including high impact measures targeting the Russian financial sector and individuals," Truss added.

For their part, the Russians have strongly denied the claim that they are planning to invade Ukraine. Russian President Vladimir Putin is concerned with the increased US and NATO presence in the region and is seeking security guarantees that NATO won't expand further eastward.

Truss insists that Russia is the "aggressor" and that NATO has always been a "defensive alliance," although since the Soviet Union collapsed, NATO has waged wars of aggression in the Balkans and across the Middle East and North Africa.

Truss' language on sanctions echoes what is coming out of Washington. The US has warned Moscow of "severe" sanctions that would aim to isolate Russia from the global financial system. In a call with President Biden last week, Putin said such sanctions could lead to the end of US-Russia relations.

On Friday, Truss and other NATO foreign ministers will hold virtual talks on Ukraine ahead of planned meetings with Russia. On January 10th, US and Russian officials will meet in Geneva to discuss Moscow's concerns. On January 12th, NATO will hold a meeting with Russian officials in Brussels.