Russian President Vladimir Putin and US special envoy Steve Witkoff. (Photo: Sputnik)

The Kremlin posted a photo on its website of the two men shaking hands, saying the meeting had taken place. "The theme of the meeting -- aspects of a Ukrainian settlement," it said.

The talks come at a time when US-Russia dialogue aimed at agreeing a ceasefire ahead of a possible peace deal to end the conflict in Ukraine appears to have stalled over disagreements around conditions for a full pause in hostilities.

Kirill Dmitriev, Putin's investment envoy, called the talks on Friday productive, according to Russian state news agency TASS.

Kremlin spokesman Dmitry Peskov said Putin and Witkoff might discuss the possibility of the Russian leader meeting Trump face-to-face.