Ukrainian President Volodymyr Zelensky resumed talks with US President Donald Trump’s envoys in Berlin on Monday, after the US side said a “lot of progress” had been made on ending Europe’s deadliest conflict since World War Two.

Zelensky again met US envoy Steve Witkoff and Trump’s son-in-law Jared Kushner after five hours of talks on Sunday, with other European leaders also holding meetings in the German capital throughout the day.

Ukraine said on Sunday it was willing to drop its ambition to join the NATO alliance in exchange for Western security guarantees, but it was not immediately clear how far talks had progressed on that or other vital issues, such as the future of Ukrainian territory, and how much the talks in Berlin could persuade Russia to agree to a ceasefire.

Zelensky said in a post on X, “There is a great deal of work underway on the diplomatic track right now,” but did not divulge details.

The Kremlin said Ukraine’s not joining NATO was a fundamental question in talks on a possible peace settlement.

Naturally, this issue is one of the cornerstones and, of course, it is subject to special discussion,“ Kremlin spokesman Dmitry Peskov told reporters.

Peskov said Russia expected an update from the US after the negotiations in Berlin.

The talks come at the start of a pivotal week for Europe, with an EU summit on Thursday set to decide whether it can underwrite a massive loan to Ukraine with frozen Russian central bank.

Europe has come under fire from the Trump administration in recent weeks over its policies on migration, security, and regulating big tech. The European Union and national governments have struggled to find a unified response to the US criticism.