Russia has indicated it's open to Ukraine joining the European Union as part of a potential peace deal to end the war, U.S. officials said Monday.

The U.S. officials who briefed reporters after U.S. envoys Steve Witkoff and Jared Kushner met with Ukrainian President Volodymyr Zelenskyy as well as British, French and German officials in Berlin over the last two days said that such an offer would be a major concession by Moscow. But Russia has previously said it does not object to Ukraine joining the EU.

The U.S. officials, who were not authorized to comment publicly by the White House and spoke on the condition of anonymity, said that the U.S. has also agreed to provide unspecified security guarantees to Kyiv as part of the deal but that such an offer won’t be on the table “forever.”

The latest round of talks between Zelenskyy and U.S. envoys ended Monday as Kyiv faces Washington’s pressure to swiftly accept a U.S.-brokered peace deal while confronting an increasingly assertive Moscow.

Ukraine's lead negotiator, Rustem Umerov, said on social media that “real progress” had been achieved at the talks in Berlin with President Donald Trump’s special envoy Witkoff and Trump’s son-in-law Kushner as well as European officials. The talks lasted roughly 90 minutes, after a five-hour session Sunday.

The U.S. government said in a social media post on Witkoff’s account after Sunday's meeting that “a lot of progress was made.”

The search for possible compromises has run into major obstacles, including control of Ukraine’s eastern Donetsk region, which is mostly occupied by Russian forces.

Zelenskyy has expressed readiness to drop Ukraine’s bid to join the NATO military alliance if the U.S. and other Western nations give Kyiv security guarantees similar to those offered to NATO members. But Ukraine’s preference remains NATO membership as the best security guarantee to prevent further Russian aggression however this option doesn’t currently have full backing from all allies.

Still, Ukraine has continued to reject the U.S. push for ceding territory to Russia. Russian President Vladimir Putin wants Ukraine to withdraw its forces from the part of Donetsk region still under its control as one of the key conditions for peace.