Ukraine's president has questioned Russia's commitment to progressing peace talks after Moscow confirmed it was sending a team to talks in Istanbul on Monday.
Russia is yet to send its negotiating proposals to Ukraine - a key demand by Kyiv. Kremlin spokesman Dmitry Peskov said Moscow's conditions for a ceasefire would be discussed in Turkey.
But Volodymyr Zelensky accused Moscow of "doing everything it can to ensure the next possible meeting is fruitless".
"For a meeting to be meaningful, its agenda must be clear, and the negotiations must be properly prepared," he said. Ukraine had sent its proposals to Russia, reaffirming "readiness for a full and unconditional ceasefire".
The first round of talks two weeks ago in Istanbul brought no breakthrough, but achieved a prisoner of war swap.
Russian President Vladimir Putin launched a full-scale invasion of Ukraine in February 2022.
Russia currently controls about 20% of Ukraine's territory, including the southern Crimea peninsula Moscow annexed in 2014.