Russia bears down on Mariupol and strikes other Ukraine cities

Zelenskyy said "all of the countries of the world" should be prepared for the possibility that Russian President Vladimir Putin could use tactical nuclear weapons in his war on Ukraine

Firefighters work to extinguish multiple fires after a Russian attack in Kharkiv, Ukraine (Felipe Dana/AP)

Russian forces pummelled a steel plant that held the last pocket of resistance on Sunday in Mariupol, a southern Ukraine city that has suffered under siege for six weeks.

With the last Ukrainian fighters in Mariupol refusing to surrender, Ukrainian President Volodymyr Zelenskyy said Russia “is deliberately trying to destroy everyone who is there”.