Officials from Ukraine started negotiations with their Russian counterparts on Monday to try to halt Russias punishing invasion of their country.

The talks began just after 1 p.m. Ukraine time, CNN reported . Several high-ranking Ukrainian officials, but not President Volodymyr Zelenskyy, attended the discussions held at a confidential location in Belarus . The two sides concluded their negotiations later in the day and said they would seek a second round.

Zelenskyys office said Ukraine wants an immediate cease-fire, but the president expressed little hope that the talks would bring an end to the fighting. Unfortunately, the Russian side is still extremely biased regarding the destructive processes it launched, Mykhailo Podolyak, an adviser to Zelenskyy, tweeted after the discussions ended Monday.

Earlier, Belarusian Foreign Minister Vladimir Makei greeted the delegations and expressed optimism.

President [Alexander] Lukashenko sincerely hopes that, during todays talks, it will be possible to find solutions to all the questions of this crisis. All Belarusians are praying for this, Makei said.

Belarus is one of Russias few close foreign partners, and on Sunday the country changed its constitution to renounce its non-nuclear status hinting that it could host Russian nuclear weapons. The U.S. and its allies have hit Russia with unprecedented sanctions in an effort to pressure the country into halting the invasion, and Russian President Vladimir Putin has responded by changing his countrys nuclear posture, triggering longstanding fears in the West.

At least 352 Ukrainian civilians have died since Putin launched a broad offensive against Ukrainian borders and cities on Thursday, according to the government in Kyiv, and at least 500,000 refugees have fled the country .

The Russians spent much of the weekend attacking Kyiv and advancing toward the city, which is home to more than 2 million people. And on Monday, just as the negotiations began, Russian forces pummeled Ukraines second-largest city, Kharkiv, killing dozens.