Ukraine-Russia crisis: What to know as tensions hit new high

Tensions over Ukraine have spiked anew

MILAN -- Tensions spiked anew over Ukraine Thursday amid conflicting claims on whether Russia had drawn down troops that could be used in an invasion, border shelling in Ukraine's separatist-controlled east and intensified diplomacy.

U.S. President Joe Biden warned there is still a “very high” risk of a Russian invasion within “several days.” And, in what the United States described as an unprovoked move, Russia expelled a senior U.S. diplomat in Moscow.

A day after Moscow said it was returning troops to bases, the NATO allies said Russia is actually building up forces near Ukraine. At the same time, separatists in the Luhansk region of eastern Ukraine are reporting an increase in Ukrainian shelling along a tense line of contact.

U.S. Secretary of State Antony Blinken, on his way to an annual security conference in Germany, was rerouted to the United Nations.