The Ukrainian Diving Federation wants diver Sofiia Lyskun to be stripped of all awards after the European champion switched her international allegiance to Russia.

Tens of thousands of people were left without power and heating in southern Ukraine after Russian night-time attacks on the frontline city of Kherson and Ukraine's largest seaport, Odesa, local authorities and the energy company said on Thursday.

Col. Gen. Vladimir Chirkin said Moscow's leadership was "unprepared" and misled into thinking 70% of Ukrainians supported Russia.

Mark Rutte's comments come a day after Putin rejected US proposals for peace in Ukraine after talks with US negotiators in Moscow.

Russian President Vladimir Putin has claimed without evidence that Russian forces have taken control of Ukrainian cities Pokrovsk and Vovchansk.

The European Union has unveiled a plan to use frozen Russian assets to support Ukraine over the next two years.