US President Biden

Asked at a news conference about the threat of a Russian invasion, he said: "My guess is he will move in, he has to do something."

But he warned that the Russian leader would pay a "serious and dear price" for "testing" the West.

Moscow denies planning to attack or invade but has built up its forces.

It is estimated to have about 100,000 troops close to Ukraine's borders.

In his first primetime address as president, Mr Biden said he would order states to make all adults eligible for vaccinations by 1 May.

Current measures prioritise people by age or health condition.

His speech comes a year to the day the outbreak was classified as a pandemic. Half a million Americans have died.

Last March, all US major sport was cancelled and actor Tom Hanks announced he had caught the virus. Then-President Donald Trump suspended travel from Europe, and also said he hoped the US would be open again for Easter.