Secretary of State Anthony Blinken announced on Monday the U.S. embassy in the Ukrainian capital of Kyiv is closing, at least temporarily, due of the buildup of Russian forces which appear poised to invade.

CBS News reports Moscow has moved long range artillery and rocket launchers into attack positions.

Some Russian units have left their assembly areas — the bumper-to-bumper formations seen in satellite photos — and are beginning to move into “attack positions,” according to the official. This movement marks a change since Sunday, when some of the units had left the assembly areas but had not yet taken what could be viewed as attack positions.

The U.S. believes Russia will attack Ukraine by the end of the week, although it’s not yet certain what form it will take, the official said. 

CBS News