Russian forces intensified their shelling of key Ukrainian cities as they failed to make “any noteworthy progress” in seizing territory, the US Pentagon said on Monday amid signs Ukrainian non-combatants were finding it increasingly difficult to escape bombardment of civilian neighbourhoods.

John Kirby, the Pentagon spokesperson, said while Russian troops were making progress in southern Ukraine, including tightening their grip around Mariupol and moving closer to the southern port of Odesa, they continued to be largely stymied in the north, where they are attempting to encircle Kyiv.

“As they continue to get frustrated, they continue to rely more on what we would call long-range fires?.?.?.?missile strikes, long-range artillery into city centres that they aren’t in yet,” Kirby said.