Biden: Russian threat to invade Ukraine still 'very high'

Fears of a new war in Europe resurged Thursday as U.S. President Joe Biden warned that Russia could invade Ukraine within days, and violence spiked in a long-running standoff in eastern Ukraine that some worried could provide the spark for wider conflict.

World dignitaries raced for solutions, but suspicions between East and West only seemed to grow, as NATO allies rejected Russian assertions it was pulling back troops from exercises that had fueled fears of an attack. Russia is believed to have built up some 150,000 military forces around Ukraine's borders.

Concerns escalated in the West over what exactly Russia is doing with those troops, which included an estimated 60 per cent of Russia's overall ground forces. The Kremlin insists it has no plans to invade, but it has long considered Ukraine part of its sphere of influence and NATO's eastward expansion an existential threat.

The U.S. government issued some of its starkest, most detailed warnings yet about what could happen next.

Speaking at the UN Security Council, U.S. Secretary of State Antony Blinken revealed some conclusions of U.S. intelligence in a strategy that the U.S. and Britain have hoped will expose and pre-empt any invasion planning. The U.S. has declined to reveal much of the evidence underlying its claims.