Talks between Ukraine and Russia are due to begin on Monday morning near the Belarusian border, reports TASS news agency.
Ukraine’s President Volodymyr Zelenskyy tells British Prime Minister Boris Johnson that the next 24 hours are a “crucial period” for Ukraine.
Ukraine’s military says Sunday was a “difficult time” for its troops and that Russian forces “continue shelling in almost all directions”.
Ukraine’s health ministry says 352 civilians, including 14 children, have been killed since the beginning of Russia’s invasion.
Russian President Vladimir Putin has put Russia’s nuclear forces on high alert.
Kharkiv governor says Ukrainian troops have full control of the country’s second-largest city after street fighting with Russian forces.