Moscow has increasingly hit critical substations linked to nuclear power plants in an effort to disconnect them. At the same time, Ukraine replaced the commander of its ground forces.

Russia's deputy U.N. ambassador said on Wednesday any decision by President-elect Donald Trump's incoming administration to cut support for Ukraine would be a "death sentence" for the Ukrainian army,

Under the alleged plan, Ukraine's western lands could be claimed by neighboring countries, while its eastern regions would be annexed by Russia and the remaining territory converted into a Russian-controlled puppet state.