Delegations from Ukraine and Russia are due to meet in Istanbul on 2 June for the next round of peace talks.
The talks will take place a day after Ukraine carried out a drone attack on strategic bombers deep behind the Russian lines, claiming the loss of dozens of aircraft.
The US State Department said Secretary of State Marco Rubio held a phone call with his Russian counterpart Sergei Lavrov on 1 June to discuss the upcoming talks.
According to the report, the call was made at Russia’s request, and Rubio reiterated US President Donald Trump’s call for continued direct talks to “achieve a lasting peace.”
At Trump’s urging, Moscow and Kiev began direct talks in May for the first time since the first weeks of Russia’s full-scale invasion, but have yet to make significant progress toward an agreement to end the war.
Ahead of the talks, experts say the chances of a breakthrough remain slim.
According to Reuters, Ukraine has put forward a number of proposals for the talks, including no obligation to have neutral status and non-recognition of the occupied territories as Russian.
Earlier, Russian media reported about the arrival of a Russian delegation in Istanbul.
On 28 May, Foreign Minister Sergey Lavrov said that Russia had offered Ukraine to meet for the second round of talks in Istanbul on 2 June. He said that the Russian side had worked out a memorandum on a peace treaty with Ukraine, which will be presented by Russian presidential aide Vladimir Medinsky.
The Kremlin refused to give Ukraine its conditions for the talks in Istanbul, which were criticized in Kiev.