A Russian delegation landed in Istanbul on Thursday for the first direct peace talks with Ukraine in more than three years, but without President Vladimir Putin as urged by many world leaders.

Putin was not included on a list of Moscow's negotiating team published by the Kremlin late on Wednesday, after Ukrainian President Volodymyr Zelensky challenged him to turn up in person at the talks.

Putin opted instead to send a lower-level team headed up by an aide who oversaw the failed peace talks in March 2022 in the first weeks of the war in Ukraine.

The absence of Putin – as well as any top diplomats like Foreign Minister Sergei Lavrov or foreign policy aide Yuri Ushakov – would seem to diminish the talks' importance or any possibility of a breakthrough.

A Ukrainian official said Zelensky planned to meet Turkish President Recep Tayyip Erdogan in Ankara, not Istanbul, later on Thursday, and only then would decide his approach to the talks.

US President Donald Trump, who has been pushing for a swift end to the war, floated the possibility of attending and had called on Putin to turn up.

US Secretary of State Marco Rubio was to travel to Istanbul on Friday "for meetings with European counterparts to discuss the conflict in Ukraine and other regional issues of mutual concern", the State Department said.

Rubio said on Thursday that Washington was "impatient" for progress in peace efforts between Ukraine and Russia, and willing to consider "any mechanism" to achieve a lasting end to the war.

"So a lot of work. We remain committed to that," he said at a Nato meeting in Turkey.

"Obviously, like everyone else, impatient, we want to see it happen, but it's difficult. But you know, hopefully progress will be made here soon."

Zelensky had spent days corralling Putin to turn up.

"This is his war... Therefore, the negotiations should be with him," he said.

The Kremlin's naming of Vladimir Medinsky as its top negotiator suggests Moscow does not plan to make any concessions at the talks.

Medinsky led the failed 2022 negotiations in which Moscow called for sweeping territorial claims and restrictions on Ukraine's military and is seen as influential in advancing Russia's historical claims over Ukrainian territory.

The other three negotiators were named as Deputy Foreign Minister Mikhail Galuzin, Deputy Defence Minister Alexander Fomin and Igor Kostyukov, director of Russia's GRU military intelligence agency.

Ukraine has not named its delegation. Its Foreign Minister Andriy Sybiga is in Turkey meeting Nato foreign ministers at a gathering in Antalya.

Putin held a briefing with his negotiating team and Russia's top foreign policy and defence officials in Moscow on Wednesday before they departed for Istanbul, the Kremlin said.

Kyiv is calling for an immediate 30-day ceasefire, and says it will not recognise its territories as Russian.

European leaders have said new sanctions will be quickly imposed on Russia if the Istanbul talks do not produce results. (AFP)