Heraldo de Madrid - Russian delegation, without Putin, arrives in Istanbul for Ukraine talks

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

Putin opted instead to send a lower-level team headed up by a hardline aide who oversaw the failed peace talks in March 2022 in the first weeks of Russia's invasion.

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.

Tens of thousands have been killed since Moscow invaded in February 2022, and Russia now occupies about a fifth of Ukraine's territory in Europe's worst conflict since World War II.

A Ukrainian official told AFP that 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.

"The president starts his visit with Erdogan in Ankara and only then will the president decide on the next steps," the official said, after Russian state media reported that Moscow's delegation had landed in Istanbul for planned talks.

Ukraine also rejected reports in Russian state media that the talks could set to start at 10:00 am (0700 GMT).

"Russian fake news," Zelensky's spokesman said when asked if that was the plan.

AFP reporters at the Dolmabahce Palace, where the talks are rumoured to be taking place, saw hundreds of journalists waiting outside.

- 'His war' -

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.

His 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.

Zelensky had spent days corralling Putin to turn up.

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

Despite the flurry of diplomacy in a bid to end the war, Moscow and Kyiv's positions remain far apart and there has been little sign either are willing to make concessions.

The Kremlin's naming of Vladimir Medinsky, a hardline aide to Putin and ex-culture minister, 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.

Medinsky 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.

- 'Cautiously optimistic' -

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, without providing details.

Russia insists the talks address what it calls the "root causes" of the conflict, including a "denazification" and demilitarisation of Ukraine, two vague terms Moscow has used to justify its invasion that are widely rejected in Kyiv and the West.

It has also repeated that Ukraine must cede territory occupied by Russian troops and pull out of some areas still under Ukraine's control.

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

But Zelensky has acknowledged that Ukraine might only get them back through diplomatic means.

NATO chief Mark Rutte said Thursday that he was "cautiously optimistic" for progress towards peace but that it was up to Russia to take the "necessary next steps".

"I'm still cautiously optimistic that if also the Russians are willing to play ball, and not only the Ukrainians are doing this... that you could get to some breakthroughs over the next couple of weeks," Rutte said at the NATO meeting.

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

Q.Escribano--HdM