Zelensky visits Ukraine's east as Russia makes push in Donbas

Ukrainian President Volodymyr Zelensky made his first trip Sunday to the war-torn east since Moscow's invasion started, as Russian forces tightened their grip around key cities in the Donbas region.

Zelensky's office posted a video on Telegram of him wearing a bullet-proof vest and being shown destroyed buildings in Kharkiv and its surroundings, from where Russian forces have retreated in recent weeks.

Since failing to capture the capital Kyiv in the early stages of the war, Russia has shifted its focus to the eastern Donbas region as it attempts to consolidate areas under its control.

Its forces said on Saturday they had captured Lyman in the contested region and were upping the pressure on the twin cities of Severodonetsk and Lysychansk.

Zelensky has been based in Kyiv since Russian President Vladimir Putin launched his full-scale attack on Ukraine on February 24.  

"In this war, the occupiers are trying to squeeze out at least some result," Zelensky said in a later Telegram post Sunday. 

"But they should have understood long ago that we will defend our land to the last man," he added.

Member states were considering excluding Russian pipeline oil as they sought to break the deadlock on a sixth round of economic sanctions, EU sources said.

On the other bank of the Donets river, Russian forces "carried out assault operations in the area of the city of Severodonetsk," according to the Ukrainian general staff.