President Vladimir Putin's launch of an Oreshnik hypersonic missile appears aimed at intimidating Ukraine and sending a signal of Russian military might to Europe and the United States at a crucial juncture in talks to end the war.

Ukraine's commander in chief said December was the first month that its drones "neutralized" roughly as many Russians as were called up.

People will be more willing to return if Ukraine is able to regain most of the territory seized by Russia since 2014, Hladun suggests. But anything short of that could leave Ukrainians feeling vulnerable as it would be considered a temporary ceasefire rather than a complete end of hostilities.

Britain said it was allocating 200 million pounds ($270 million) to fund preparations for the possible deployment of troops to Ukraine, after pledging its soldiers this week

NATO allies in the Coalition of the Willing are planning security guarantees for Ukraine once Russia's war is over.

Russia's overnight attack on Ukraine's energy infrastructure leaves nearly 800,000 homes without power amid freezing winter temperatures across the country.

US President Donald Trump has said he is ready to assume commitments regarding US participation in future security guarantees for Ukraine because he believes that Russia will not attempt another invasion.

Russia said on Thursday that any troops sent to Ukraine by Western governments would be "legitimate combat targets", after France and Britain announced plans to deploy a multinational force there in the event of a ceasefire.