A Russian negotiator said Moscow hopes for "some progress" in Monday’s talks in Saudi Arabia, where the U.S. is set to hold separate meetings with Ukrainian and Russian delegations to seek an end to the three-year conflict.
U.S. envoy Keith Kellogg described the effort as "shuttle diplomacy" between hotel rooms.
Ukraine will meet the U.S. mediators first, with President Volodymyr Zelenskyy saying he was "prepared" for Sunday's talks.
A separate meeting between U.S. and Russian officials in the Gulf kingdom is scheduled Monday.
Moscow has rejected a joint U.S.-Ukraine proposal for a full and unconditional 30-day cease-fire, countering with a suggested pause on aerial attacks on energy facilities.
Both Moscow and Kyiv have continued exchanging strikes in the run-up to the negotiations.
Despite the flurry of diplomacy and push from U.S. President Donald Trump, a breakthrough has so far proved elusive.
"We hope to achieve at least some progress," Russian senator Grigory Karasin, who will lead the Russian delegation, told the Zvezda TV channel, without specifying on what issue.
He said he and fellow negotiator, FSB advisor Sergey Beseda would take a "combative and constructive" mood into the talks.
A senior Ukrainian official told AFP a day earlier that Kyiv hopes to secure agreement "at least" on a partial cease-fire covering attacks on energy, infrastructure and at sea. Kyiv is sending its defense minister to the negotiations.
"We are going with the mood to fight for the solution of at least one issue," Karasin told Zvezda, which is owned by Russia's Defense Ministry.
He said they were leaving for Saudi Arabia on Sunday and would return on Tuesday.
Russia's choice of negotiators for the talks has raised questions. Both are outside of traditional diplomatic decision-making institutions such as the Kremlin, Foreign Ministry or Defense Ministry.
Karasin is a career diplomat, who now sits in Russia's upper house of parliament, while Beseda is a long-time FSB officer and now an advisor to the security service's director.
The FSB in 2014 admitted that Beseda was in Kyiv during a bloody crackdown in the Ukrainian capital amid the country's pro-EU revolution.
Ukraine has accused Russia of not genuinely seeking peace and condemned its ongoing attacks, despite Russian President Vladimir Putin saying Tuesday he had ordered his army to stop targeting Ukrainian energy sites.
In contrast, a U.S. official close to Trump, White House envoy Steve Witkoff, has praised Putin – whom he met in Moscow last week – as a "great" leader seeking to end the conflict with Kyiv.
"I thought he was straight up with me," Witkoff told an American right-wing podcast host, Tucker Carlson, in an interview that aired Friday.
"I don't regard Putin as a bad guy. That is a complicated situation, that war, and all the ingredients that led up to it," Trump's envoy said.
Russia fired 179 drones at Ukraine in its latest overnight barrage, the Ukrainian air force said Saturday.
In the southern city of Zaporizhzhia, an entire family, including a 14-year-old girl, was killed when a drone crashed into their house Friday, the regional authorities said.
An AFP photographer at the scene of one strike saw rescue workers sifting through the rubble of a destroyed building, as smoke and fog hung in the night air.
In the eastern Donetsk region, Russian strikes on Saturday killed at least two people and wounded three, according to the local governor.
Zelenskyy meanwhile said he had visited troops fighting to defend the embattled eastern city of Pokrovsk, which Russia has been trying to encircle and capture for months.
