Russia on Thursday urged residents and diplomats to leave Kyiv for the second time in less than 24 hours, warning of a potential retaliatory strike during a unilateral ceasefire Moscow declared around its WWII victory holiday on May 9.

"We remind the civilian population of Kyiv and staff at foreign diplomatic missions once again of the need to leave the city in good time," the defence ministry said in a statement, promising to "answer in kind" in case of a Ukrainian attack.