Each side is due to meet on Friday with Marco Rubio, the US Secretary of State, and Turkey's foreign minister, Hakan Fidan, but still without any broader meeting planned.

Putin's absence punctured hopes of a breakthrough in peace efforts that were given a push in recent months by the Trump administration and Western European leaders.

President Volodymyr Zelensky arrived in Turkey on May 15 ahead of potential ceasefire negotiations with Russia, even as Russian President Vladimir Putin is skipping the talks. Zelensky's plane has landed at the Ankara airport.