American allies and Ukrainian officials were scrambling on Wednesday to understand the terms of a Trump administration peace proposal for Ukraine, with many worrying it meant the U.S. could cave to Russian demands in a rush to end the fighting.

As European and U.S. officials alike sought clarity, they said many aspects of the plan remained in flux, including the role of NATO and any Ukrainian territorial concessions to Russia.

The effort by Trump administration’s peace envoy Steve Witkoff — who has been serving as an interlocutor with Moscow — began late last month when he met with Russian special envoy Kirill Dmitriev in Miami, according to one person familiar with the matter, just as President Donald Trump’s hopes for a meeting with Russian President Vladimir Putin fell apart.

Ukrainian and European officials felt blindsided as the existence of Witkoff’s plan became public, a pain particularly sharp because they felt Trump had finally begun to realize Putin’s insincerity in reaching a settlement, said the person and another familiar with the matter.

The people, like others in this story, were granted anonymity to discuss sensitive diplomacy.

The 28-point plan — the existence of which was first reported by Axios — would in its current form require significant concessions from Ukraine, including restraints on its military and giving up major territorial tracts, according to a third person familiar with the effort. But the person stressed that the provisions of the plan remained negotiable.

One aspect U.S. officials are still pondering is whether and how to mention NATO, the person said. The discussion of NATO has not been previously reported.

Ukraine has sought NATO membership as a security guarantee against a future Russian invasion. While some European countries support that, the U.S. has rejected it and Moscow has long demanded Kyiv not join the defensive alliance, viewing that as a threat. The European allies also worry about granting Russia territorial concessions, which they see as rewarding Moscow’s aggression and setting a concerning precedent.

The White House declined to comment on the specifics of the plan or how it came about.

In European capitals, officials were trying to make sense of a plan with few details to go on.

“We have not been briefed on this,” German Foreign Minister Johann Wadephul told reporters Wednesday. “There are ongoing efforts by all international partners to finally get President Putin to the negotiating table.”

He added: “We naturally support everything that leads in this direction. We are focusing on supporting Ukraine and thus making it very clear to Putin that there is no alternative to a negotiation process.”

Russia’s demands appeared to repeat proposals Secretary of State Marco Rubio had already rejected in the effort to negotiate a leaders summit and that would be unacceptable to Kyiv, the first person familiar with the matter said. These include Moscow’s repeated demand that it control more territory in Eastern Ukraine than it has captured in the war and that Ukraine give up future security protections from Western allies.

Army Secretary Dan Driscoll, along with Army chief of staff Gen. Randy George and Army Europe commander Gen. Christopher Donahue, were hastily dispatched to Kyiv this week to talk to the Ukrainians about the plan, as POLITICO first reported Tuesday.

The trip came together quickly after a White House meeting last week in which Trump said Driscoll — who was planning a trip to Ukraine next month — should be the emissary to Ukrainian President Volodymyr Zelenskyy and his team about the plan, according to an administration official. Driscoll will follow up his meetings in Kyiv with a series of briefings with NATO allies to catch them up on the plan and what the U.S. sees as the way forward, the official added.

The White House has been bullish about the burgeoning plan, with one senior White House official saying a framework for ending the conflict could be agreed to by all parties by the end of this month, and even “as soon as this week.” A second White House official said both sides will need to show flexibility.

Ukraine hasn’t commented publicly about the plan. Zelenskyy’s chief of staff Andriy Yermak said Wednesday he is in “constant communication” with Trump’s team, including Witkoff, and would work with the U.S. to end the war “and secure a just and lasting peace.”

U.K. Foreign Minister Yvette Cooper noted that Putin has rebuffed all of Trump’s peace efforts so far and has instead “simply chosen to escalate the war.” This is why, she said, the European approach is to pressure Putin, through economic sanctions and support for Ukraine, to come back to the table for peace talks.

One U.K. diplomat indicated London had not been briefed on the proposals, despite national security adviser Jonathan Powell’s close relationship to Witkoff. A second British official sought to downplay how seriously the plan should be taken.

European and Ukrainian officials have for months been wary of Witkoff’s approach to the conflict.

Some have blamed his penchant for working alone for the failure of the administration’s peace efforts so far, with his refusal to consult allies leaving him at times uninformed or unprepared, as POLITICO has reported. They see his quiet consultations with Russia as an example of how he has been misled by Russia about the nature of the conflict and Putin’s true aims.

“The Russians have clearly identified Witkoff as someone who is willing to promote their interests,” said one EU defense official. “Europeans have not been consulted on this. But there’s a wing inside the White House who for some time have seen Europeans as ‘spoilers’ in the peace process, so in a way, it’s not surprising.”

The second White House official dismissed those with concerns that Moscow wants to work only with Witkoff to end the war. Russia should want to talk to Washington about ending the war, the official said.

The Kremlin on Wednesday played down the significance of the new proposal.

“There has been nothing new in addition to what was discussed in Anchorage,” Putin’s spokesperson Dmitri Peskov said when asked about the proposal, referring to the Alaska summit between Trump and Putin in August.

It’s unclear how extensive the planning has been for this peace plan. A number of people who would normally have been informed of such a plan at the White House and State Department were also not consulted about Witkoff’s renewed push, according to the first and third individuals familiar with the matter.

The first person said that Witkoff’s plan involved “zero interagency coordination.” The White House did not immediately respond to a request for comment on whether he followed the usual interagency process, which would require seeking inputs from relevant departments across government.

Since taking office in January, Trump and senior aides have repeatedly tried to get Russia to engage seriously in ending the conflict. But months of high-level meetings and phone calls, including the Alaska summit, have left Trump and his team frustrated and empty-handed.

After months of refusing to levy any financial penalties on Moscow, Trump sanctioned Russia’s two largest oil companies in October after plans for a meeting between Trump and Putin in Budapest fell apart.

Driscoll, the top defense official dispatched to Ukraine, had already been involved in working with the Ukrainians on sharing some of their drone expertise, and that deal, which Trump is eager to get done, is also part of the talks this week. Trump has dubbed Driscoll his “drone guy” according to the administration official, and he has won the president’s trust with his push to reform the Army’s weapons acquisition bureaucracy and his more frequent appearances on national tv to tout his reforms.

Diana Nerozzi and Nette Nöstlinger contributed to this report.