Dhaka: The United States closed its airspace to Russian planes as the Russian military attempted to encircle and subdue Ukrainian cities with intensifying bombardments on March 2, almost a week into an invasion that has sparked massive international sanctions.

Already shunned by the West over its invasion of Ukraine, Russia has shown no sign of stopping an assault that has included strikes on Kyiv and rocket attacks in the second city of Kharkiv. Dozens have been killed.

Russia has failed to capture a single city since its full-scale invasion began nearly a week ago, and Western analysts say Moscow has fallen back on tactics which call for devastating shelling of built-up areas before entering them.

Hundreds of thousands of Ukrainians have fled the fighting as a miles-long Russian military convoy north of Kyiv advances toward the city. West of Kyiv, in the city of Zhytomyr, four people, including a child, were killed on Tuesday by a Russian cruise missile, a Ukrainian official said.

Ukrainian President Volodymyr Zelenskiy called on Russia to stop bombarding civilians and resume talks.

"It's necessary to at least stop bombing people, just stop the bombing and then sit down at the negotiating table," he said.