Two days after Ukraine called for new talks in Istanbul this week, Russian state news agency TASS quoted an unidentified source as saying that negotiators - who have not sat down together for seven weeks - may meet there on Thursday and Friday.
Ukrainian President Volodymyr Zelenskiy told a gathering of his diplomats in Kyiv: "We need greater momentum in negotiations to end the war."
He added: "The agenda from our side is clear: the return of prisoners of war, the return of children abducted by Russia and the preparation of a leaders' meeting."
Russian President Vladimir Putin, who is under increasing pressure from US President Donald Trump to show progress towards ending the conflict, turned down a previous challenge from Zelenskiy to meet him in person.
Putin has repeatedly said he does not see Zelenskiy as a legitimate leader because Ukraine, which is under martial law, did not hold new elections when his five-year mandate expired last year.
Kremlin spokesman Dmitry Peskov said that as soon as there was a definitive understanding of the date for the next round of talks, then Russia would announce it.
"There is our draft memorandum, there is a draft memorandum that has been handed over by the Ukrainian side. There is to be an exchange of views and talks on these two drafts, which are diametrically opposed so far," Peskov said.
Ukraine and Russia have held two rounds of talks in Istanbul, on May 16 and June 2, that led to the exchange of thousands of prisoners of war and the remains of dead soldiers.
But the two sides have made no breakthrough towards a ceasefire or a settlement to end almost three and a half years of war.
Trump said last week he would impose new sanctions in 50 days on Russia and countries that buy its exports if there is no deal before then to end the conflict.
