Russia has indicated it's open to Ukraine joining the European Union as part of a potential peace deal aimed at ending Russia's war on Ukraine, and there's now consensus on about 90% of the U.S.-authored peace plan, U.S. officials said Monday.

The officials said robust negotiations between President Donald Trump's envoys, Steve Witkoff and Jared Kushner, and Ukrainian President Volodymyr Zelenskyy and his team led to progress on narrowing differences on security guarantees that Kyiv said must be provided to Ukraine as well as the contentious issue on Moscow's demand that Ukraine concede land in the eastern Donbas.

Kushner and Witkoff are expected to meet over dinner on Monday evening with Ukrainian as well British, German and French leaders for further talks.

Trump, who has been briefed twice on the Berlin talks, plans to dial in to the dinner from Washington.

The negotiators and others involved in the peace talks will likely meet in Miami or elsewhere in the U.S. this weekend to continue their work, according to the U.S. officials.

The U.S. officials also said the administration plans to put forward the security guarantees agreement before the Senate for its approval, although they didn't specify whether it would be ratified like a treaty, which needs two-thirds approval from the chamber.

The U.S. officials who briefed reporters after Witkoff and Kushner met with Zelenskyy and other European officials in Berlin the past two days said that such an offer over Ukraine joining the EU would be a major concession by Moscow.

But Russia 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 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 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.

Ukraine's preference remains NATO membership as the best security guarantee to prevent further Russian aggression, yet this option doesn't have 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.

Zelenskyy's itinerary on Monday also included meetings with German and other European leaders. French President Emmanuel Macron's office confirmed he would travel to Berlin later Monday.

"The issue of security in particular will ultimately determine whether this war actually comes to a standstill and whether it flares up again," a spokesperson for German Chancellor Friedrich Merz, Stefan Kornelius, told reporters.

The Russian president has cast Ukraine's bid to join NATO as a major threat to Moscow's security and a reason for launching the invasion in February 2022.

The Kremlin has demanded that Ukraine renounce the bid for alliance membership as part of any prospective peace settlement.

Zelenskyy emphasized that any Western security assurances would need to be legally binding and supported by the U.S. Congress.

The Kremlin said Monday it expected to be updated on the Berlin talks by the U.S. side.

Asked whether the negotiations could be over by Christmas, Kremlin spokesperson Dmitry Peskov said trying to predict a potential time frame for a peace deal was a "thankless task."

"I can only speak for the Russian side, for President Putin," Peskov said. "He is open to peace, to a serious peace and serious decisions. He is absolutely not open to any tricks aimed at stalling for time."

Putin has denied plans to attack any European allies.

In London, meanwhile, the new head of the MI6 spy agency was set to warn on Monday how Putin's determination to export chaos around the world is rewriting the rules of conflict and creating new security challenges.

Blaise Metreweli was using her first public speech as chief of the U.K.'s foreign intelligence service to say that Britain faces increasingly unpredictable and interconnected threats, with emphasis on "aggressive, expansionist" Russia.

Russia fired 153 drones of various types at Ukraine overnight Sunday into Monday, according to Ukraine's air force, which said 133 drones were neutralized while 17 more hit their targets.

In Russia, the Defense Ministry on Monday said forces destroyed 130 Ukrainian drones overnight. An additional 16 drones were destroyed between 7 a.m. and 8 a.m. local time.

Eighteen drones were shot down over Moscow itself, the defense ministry said. Flights were temporarily halted at the city's Domodedovo and Zhukovsky airports as part of safety measures, officials said.

Damage details and casualty figures were not immediately available.