Ukrainian President Volodymyr Zelensky called for speedier weapons deliveries from the West as Russian forces increase pressure on the country’s defenders.

Russian forces have battered Ukrainian positions in the country’s east in recent weeks, pushing for a breakthrough before tanks pledged by Kyiv’s partners begin to arrive on the battlefield. In the eastern Donetsk region, Ukrainian troops are coming under constant attack from Russian forces, Mr. Zelensky said in his nightly address, describing the situation as “very tough.”