Russia expected to try to encircle Kyiv in coming days -U.S. official

New members of the Ukrainian Territorial Defence Forces train with newly received weapons in Kyiv, Ukraine February 28, 2022. REUTERS/Gleb Garanich

WASHINGTON (Reuters) -The United States expects Russian forces to try to encircle Kyiv in the coming days and could become more aggressive out of frustration with their slow advance on the Ukrainian capital, a senior U.S. defense official said on Monday.

Air raid sirens wailed across the largely empty streets of Kyiv on Monday warning of another possible missile attack by Russia as the city girds for worse battles to come as Russian forces approach.