U.S. puts troops on alert as Ukraine tensions rise

PENTAGON SPOKESMAN JOHN KIRBY: "It's very clear that the Russians have no intention right now of de-escalating."

The Pentagon announced on Monday that it was putting 8,500 troops on heightened alert to be ready for possible deployment to Europe, in the latest effort to reassure nervous NATO allies, as Russia masses troops on the border with Ukraine.

KIRBY: "There's been no mission assigned right now. This is about getting troops ready."

Pentagon spokesman John Kirby stressed that no decision had been made yet on whether to deploy the troops, and that they would fill in the ranks of a NATO rapid response force, should Russia invade Ukraine.

So far, NATO has about 4,000 troops in multinational battalions in eastern Europe.

NATO SECRETARY GENERAL JENS STOLTENBERG: "We are considering to further enhance our presence in the eastern part of the alliance."

In a tweet, NATO's Secretary-General said "any further aggression by Russia against Ukraine will have severe costs," which he posted after an online meeting with U.S. President Joe Biden, and the leaders of France, Germany, Italy, Poland, Britain and the European Union.

Russia has called the moves Western "hysteria" and denies planning an invasion.

But having surrounded Ukraine with an estimated 100,000 troops from the north, east and south, Moscow is now citing the Western response as evidence that Russia is the target, not the instigator, of aggression.

Meanwhile, Britain said it was withdrawing some staff and dependents from its embassy in Ukraine, a day after the U.S. said it was ordering diplomats' family members to leave the country.