Russian President Vladimir Putin sent a second-tier team of aides and deputy ministers to hold peace talks with Ukraine in Turkey on Thursday, spurning Kyiv's challenge to go there in person to meet President Volodymyr Zelenskiy.

Putin's no-show plunged prospects for the talks - which would be the first since the early weeks of the war - into confusion. Russia said they would take place in Istanbul in the second half of the day, but Turkey said no meeting was scheduled yet.

Zelenskiy, arriving in the Turkish capital Ankara, described the Russian line-up - excluding Putin, his foreign minister and his top foreign policy adviser - as "decorative". He said Ukraine would decide its next move on talks with Russia after he had met Turkish President Tayyip Erdogan.

"We need to understand what kind of level the Russian delegation is, and what mandate they have and whether they can make any decisions," he said.

Asked what his message to Putin would be, Zelenskiy told reporters at the airport: "I'm here. I think this is a clear message."

Russia said its team was in Istanbul and ready for serious work, and accused Ukraine of "trying to put on a show" around the negotiations.

Both sides have been wrestling for months over the logistics of ceasefires and peace talks while trying to show US President Donald Trump they are serious about trying to end what he calls "this stupid war".

Hundreds of thousands have been killed and wounded on both sides in the deadliest conflict in Europe since World War Two. Washington has threatened repeatedly to abandon its mediation efforts unless there is clear progress.

Russia said on Thursday its forces had captured two more settlements in Ukraine's Donetsk region. A spokeswoman for Russian Foreign Minister Sergei Lavrov pointedly reminded reporters of his comment last year that Ukraine was "getting smaller" in the absence of an agreement to stop fighting.

Pressure from Trump

There was confusion in Istanbul, where reporters were gathered near the Dolmabahce palace that the Russians had specified as the talks venue.

Zelenskiy had goaded Putin earlier this week by questioning if he was brave enough to show up. The Kremlin says Putin - who is also under threat of even tighter European sanctions to "suffocate" Russia's economy - does not respond to ultimatums.

The warring sides last held face-to-face talks - also in Istanbul - in March 2022, only weeks after Putin sent his army into Ukraine.

After leaning heavily on Ukraine and clashing with Zelenskiy at an Oval Office meeting in February, Trump has shown increasing impatience with Putin in recent weeks and threatened additional sanctions to hit Russian trade.

The US president, who is on a three-nation tour of the Middle East, said on Thursday he would go to the talks in Turkey on Friday if it was "appropriate".

"I just hope Russia and Ukraine are able to do something. It has to stop," he said.

'Not the Key Players'

US Secretary of State Marco Rubio, speaking at a NATO meeting in Turkey, said there was no military solution to the conflict, and Trump was open to "virtually any mechanism" that would lead to peace.

If the talks do go ahead, they will have to address a chasm between the two sides over a host of issues.

Zelenskiy backs an immediate 30-day ceasefire, but Putin has said he first wants to start talks at which the details of such a truce could be discussed.

With Russian forces in control of close to a fifth of Ukraine, Putin has held fast to his longstanding demands for Kyiv to cede territory, abandon its NATO membership ambitions and become a neutral country.

Ukraine rejects these terms as tantamount to capitulation, and is seeking guarantees of its future security from world powers, especially the United States.

The Russian delegation is headed by presidential adviser Vladimir Medinsky and includes a deputy defence minister, a deputy foreign minister and the head of military intelligence.

The Kremlin said Putin had held a late-night meeting with ministers, military commanders and spy chiefs to discuss the upcoming talks.

A source involved on the Ukrainian side in the March 2022 talks in Istanbul said that Medinsky - who also led the Russian team then - did not have a strong mandate to make decisions.

"The people who will actually be sitting at the table are not necessarily the key players," the source said.

French Foreign Minister Jean-Noel Barrot said Zelenskiy had shown his good faith by coming to Turkey but there was an "empty chair" where Putin should be sitting.

"Putin is stalling and clearly has no desire to enter these peace negotiations, even when President Trump expressed his availability and his desire to facilitate these negotiations," he said.

Estonia, an EU and NATO member, said Putin was delivering a "slap in the face" by sending a low-level team.

Highlighting the level of tension between Russia and the US-led alliance, Estonia said a Russian fighter jet had "violated NATO territory" as the Estonian navy tried to detain a Russia-bound oil tanker under British sanctions.