Russia said on Saturday that fighting had been taking place in four regions of Ukraine despite this week's unilateral ceasefire by Moscow, saying its troops had been forced to respond to Ukrainian attacks.

Ukrainian President Volodymyr Zelenskyy announced that Ukraine was ready to accept a U.S. proposal for a 30-day cease-fire, provided Russia did the same.

Ukraine and its European allies have called for Russian President Vladimir Putin to agree to a 30-day ceasefire, which could start as early as Monday, after the leaders of Germany, France, the United Kingdom and Poland arrived in Kyiv on Saturday.