MOSCOW, Dec. 15 (Xinhua) -- The United States has not shared with Russia the proposals discussed with Kiev to resolve the Ukraine crisis, Kremlin spokesman Dmitry Peskov said on Monday.

Ukrainian President Volodymyr Zelensky arrived in Berlin on Sunday for talks with a U.S. negotiating team led by White House special envoy Steve Witkoff and U.S. President Donald Trump's son-in-law Jared Kushner.

Following the five-hour talks, Witkoff said on social media that "a lot of progress" had been made.

However, the U.S. side has yet to provide Russia with any details of the vision presented during the discussions, Peskov noted, adding that Moscow hopes to see concrete proposals for resolving the Ukraine issue once the talks are concluded.

Earlier on Sunday, Zelensky said Ukraine would be willing to abandon its bid to join NATO if it received security guarantees from the United States and European countries based on NATO's Article 5.

Peskov stressed that guarantees ensuring Ukraine's non-accession to NATO constitute one of Russia's fundamental positions, describing the issue as "one of the cornerstones" of any settlement process. ■