War rivals Ukraine and Russia are set to go into their first direct talks in more than three years, with Russian President Vladimir Putin not included on the list of attendees.
Russia's delegation arrived in Türkiye on Thursday for the negotiations on a possible ceasefire with Ukraine, the Russian RIA Novosti news agency reported.
"The Russian delegation has landed" in Istanbul, a source told the agency.
NATO chief Mark Rutte said “Türkiye plays a big role here because it has good relations with all relevant partners and is seen as a serious venue.”
Ukraine's President Volodymyr Zelenskyy had challenged Putin to meet him in person in Istanbul, but the Russian delegation names only a lower-level team.
A Ukrainian official said there had been no agreement on when talks with Russia in Türkiye might start, dismissing reports from Russian media.
Andriy Kovalenko, an official at Ukraine's National Security and Defence Council, said on the Telegram app that the 10 a.m. (0700 GMT) start of the talks "was not planned and was not true".
Tens of thousands have been killed since the offensive started in February 2022. Russia has occupied about a fifth of Ukraine's territory in what is one of Europe's worst conflicts since World War 2.
Putin had proposed holding talks on May 15 in Istanbul as a counter-offer after Ukraine and European nations last week called for a 30-day unconditional ceasefire.
Zelenskyy agreed, but said this week that if Putin did not attend himself, it would signal he was not genuinely interested in peace.
"This is his war... Therefore, the negotiations should be with him," Zelensky said.
The Kremlin delegation is set to be headed by Vladimir Medinsky, a hardline aide to Putin and ex-culture minister who was involved in the 2022 negotiations.
Putin, Foreign Minister Sergey Lavrov and Kremlin foreign policy aide Yuri Ushakov — who had all been rumoured as top negotiators after leading previous talks with the United States — were not named in the Kremlin's delegation list.
Thursday could mark a pivotal moment in global efforts to halt Russia-Ukraine war as both sides are expected to hold direct talks in the Turkish city of Istanbul.
Europe's sanctions warning
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.
European leaders have said new sanctions will be quickly imposed on Russia if the Istanbul talks do not produce results.
On the eve of the talks, Zelenskyy said he would decide Ukraine's next "steps" based on who represents Moscow.
"Ukraine is ready for any format of negotiations, and we are not afraid of meetings. Tomorrow "in Türkiye," Zelensky said. "I am waiting to see who will arrive from Russia. Then I will decide what steps Ukraine should take."
Russia insists the talks address what it calls the "root causes" of the conflict, including the "denazification" and demilitarisation of Ukraine.
It has also repeated that Ukraine must cede territory occupied by Russian troops.
Kiev said it will not recognise its territories as Russian — though Zelenskyy has acknowledged that Ukraine might only get them back through diplomatic means.
US Secretary of State, Marco Rubio, will be in Istanbul on Friday. Rubio met Ukraine's Foreign Minister Andriy Sybiga at a NATO meeting in Türkiye on Wednesday.
And US President Donald Trump on Wednesday indicated he could take a mediation role in Türkiye.
"I don't know that he (Putin) would be there if I'm not there," Trump told reporters accompanying him on a Middle East tour.
"I know he would like me to be there, and that's a possibility. If we could end the war, I'd be thinking about that," he said.
