Turkish Foreign Minister Mevlut Cavusoglu said on Thursday that Russian oligarch Roman Abramovich, who is sanctioned by European nations over Russia's invasion of Ukraine, was "sincerely" working to end the war.

He has been liaising between Kyiv and Moscow since the invasion began on Feb. 24, Cavusoglu said.

Abramovich made a surprise appearance at Ukraine-Russia negotiations in Istanbul on Tuesday.

(Reporting by Tuvan Gumrukcu and Ece Toksabay; Writing by Jonathan Spicer Editing by Gareth Jones)