The FT said the annexation of Donetsk would give Moscow full control of the strategic part of eastern Ukraine, which it has partially occupied for more than a decade. Russian troops have been rapidly gaining ground there since November, bringing Moscow's control to about 70 percent, but Kiev still controls the westernmost cities.

However, Putin did not abandon his demand that Ukraine be a neutral country outside military blocs.

According to the British newspaper's sources, Zelensky would not agree to the surrender of the Donetsk region, but is ready to negotiate territorial concessions in exchange for ending the war, which Russia has been waging in full force for more than three years.