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.
"We expect that they're going to want to continue to move forward and try to encircle the city in the coming days," the official said, adding that Russian troops were about 25 km (16 miles) from Kyiv's city center.
U.S. officials believe that stiff Ukrainian resistance has slowed the progress of Russian troops and planning failures have left some Russian units without fuel or other supplies.
"One of the things that could result is a reevaluation of their tactics and the potential for them to be more aggressive and more overt, in both the size and scale of their targeting of Kyiv," the official told reporters.
The official, who was speaking on the condition of anonymity and did not provide evidence, said the United States had yet to see this happen but was concerned about it.
Russian forces, now in the fifth day of an invasion of their Ukrainian neighbor, have fired about 380 missiles at Ukrainian targets, the official said, and President Vladimir Putin has committed nearly 75% of his pre-staged combat power into Ukraine.
(Reporting by Phil Stewart and Idrees Ali; Editing by Howard Goller)
