Russian President Vladimir Putin made a surprise visit to Mariupol, Russian state media reported on Sunday, in what would be the Kremlin leader's first trip to the Russian-occupied territories of Ukraine's Donbas region since the start of the war.

The visit came after Putin traveled to Crimea on Saturday in an unannounced visit to mark the ninth anniversary of Russia's annexation of the peninsula from Ukraine, and just two days after the International Criminal Court (ICC) issued an arrest warrant for the Russian leader.

Putin has yet to comment publicly on the ICC warrant, but his trips into Ukrainian territory claimed by Russia was seen by some observers as an act of defiance.