The source, speaking on condition of anonymity, added that the meeting was discussing some of the"most sensitive issues" related to ending the conflict."So far, everything is fine," he said.

Meanwhile, Ukrainian First Deputy Foreign Minister Serhiy Kyslytsia gave a positive assessment of the negotiations via social media. The meeting"is constructive so far. A pleasant atmosphere that is conducive to potential progress," he wrote on the social network X.

A source told CNN ahead of the meeting that despite some progress in the talks, fundamental differences remain in at least three key areas. These include whether Ukraine should cede the entire Donbas region in the east of the country to Russia, whether it should commit to limiting the size of its army to a maximum of 600,000 soldiers, and whether it should never join NATO.

Ukraine has minimal chance of a more favorable agreement, says analyst Smetana. Why can't the West come up with a better plan?

In Moscow, these three issues – the cession of territory, the demilitarization of Ukraine and its exclusion from future NATO membership – are the most frequently cited by Kremlin leader Vladimir Putin as reasons for starting the war. However, these demands are clearly rejected by Kiev and its European allies.

The Ukrainian delegation is led by Secretary of the National Security and Defense Council Rustem Umerov."I am in constant contact with the President of Ukraine (Volodymyr Zelensky). We have clear guidelines and priorities - protection of Ukrainian interests, substantive dialogue and progress based on the results achieved in Geneva," Umerov wrote on the Telegram social network. He added that the goal is to achieve"real" peace.

Ukrainian negotiators are meeting with senior US administration officials – US Secretary of State Marco Rubio, Special Envoy Steve Witkoff and Jared Kushner, son-in-law and advisor to President Donald Trump.

Rubio said he expected"greater progress" from the meeting toward an agreement to end the war in Ukraine."This is not just about peace agreements. This is about creating a path forward that leaves Ukraine sovereign, independent and prosperous. We expect to make even greater progress today," the US secretary added.

The second round of talks follows a meeting in Geneva, Switzerland, a week ago. The original US draft peace plan, which leaned heavily towards Moscow's demands, was subsequently revised during the meeting.

The US side also emphasized that the proposal remains a"living and evolving document" that is being adjusted based on feedback from partners.

It is not yet clear what Russia's stance on the terms being negotiated will be. The US team is expected to travel to Moscow next week for talks with Russian leader Vladimir Putin, CNN reported.