Russia said it was still waiting for Ukraine to commit to new talks in Istanbul on Monday, after Kiev demanded Moscow send its peace terms before pledging to attend the meeting.
Diplomatic efforts to end the three-year conflict have gained pace in recent months, but Russia has maintained an intense bombardment of Ukraine and repeatedly rebuffed calls for an immediate ceasefire.
Moscow offered to hold a second round of direct talks with Ukraine in Istanbul on June 2, when it said it would present a "memorandum" outlining its conditions for a long-term peace settlement.
Ukraine said the meeting would not yield results unless it saw a copy of the memorandum in advance, a proposal the Kremlin dismissed.
"As far as I know, no response has been received yet... we need to wait for a response from the Ukrainian side," Kremlin spokesman Dmitry Peskov said, calling Kiev's demand to hand over its peace terms "non-constructive".
Ukraine said it had already submitted its vision of a peace settlement to Russia and demanded Moscow do the same.
Ukrainian President Volodymyr Zelenskyy said Russia was "doing everything they can to make the meetings empty.
And this is another reason why there must be sufficient sanctions, sufficient pressure on Russia."
"We continue to urge (Russia) to share this document," said Ukrainian foreign ministry spokesperson Georgiy Tykhy.
Moscow's refusal to send the document "suggests that it is likely filled with unrealistic ultimatums", he said.
Turkish Foreign Minister Fidan reiterated Türkiye’s commitment to facilitating dialogue and stressed that both sides must reconcile differing ceasefire demands.
'Shut the door'
Türkiye's President Recep Tayyip Erdogan called on Russia and Ukraine not to "shut the door" on dialogue ahead of the anticipated second round of talks in Istanbul.
Negotiations in Istanbul on May 16, the first direct talks on ending the conflict in more than three years, yielded only a prisoner exchange and promises to stay in touch.
Russian foreign ministry spokesperson Maria Zakharova told state television the Kremlin planned to send the same negotiating team as was at the earlier talks. That was led by Vladimir Medinsky, a Kremlin aide who also took part in talks in 2022 in the weeks after Russia launched its offensive.
After the May 16 talks, Ukraine accused Russia of outlining unrealistic demands, including calls to cede territory Kiev still controls.
The Russian offensive, launched in February 2022, has resulted in tens of thousands of deaths and the destruction of large parts of eastern and southern Ukraine.
Russian forces have moved forward on the battlefield while pushing peace demands that include Ukraine abandoning its NATO ambitions and giving up around a fifth of its land.
The Russian army said Thursday it had captured three villages in Ukraine's Donetsk and Kharkiv regions in its latest advance.
Türkiye's Foreign Minister Hakan Fidan was expected to travel to Kiev on Thursday to meet Zelenskyy, after talks with Russian President Vladimir Putin in Moscow on Monday.
US President Donald Trump, who has been pushing for a peace deal, has become increasingly frustrated with Moscow's apparent stalling, and warned Wednesday he would determine within "about two weeks" whether Putin was serious about ending the fighting.
Local authorities in Ukraine said on Thursday that Russia had fired 90 drones overnight.
At least seven people were killed in drone, missile and artillery strikes across five frontline Ukrainian regions, officials said.
Russia said it had repelled 48 Ukrainian drones overnight, including three near Moscow.
Trump told reporters he was "very disappointed" at Russia's deadly bombardment during the negotiating process, but rebuffed calls to impose more sanctions on Moscow.
Kiev has accused Russia of deliberately stalling the peace process to pursue its offensive.
Zelenskyy earlier this week said Russia was "amassing" more than 50,000 troops on the front line around Sumy, where Moscow's army has captured a number of settlements as it seeks to establish what Putin has called a "buffer zone" inside Ukrainian territory.
Russian Foreign Minister held a phone call Wednesday with US Secretary of State Marco Rubio to discuss possible Russian-Ukrainian peace talks in Istanbul, Türkiye.
