U.S. President Donald Trump has paused military aid to Ukraine following his clash with Ukrainian President Volodymyr Zelenskiy last week, a White House official said, deepening the fissure that has opened between the two one-time allies, Reuters reported.

The move comes after Trump upended U.S. policy on Ukraine and Russia upon taking office in January, adopting a more conciliatory stance towards Moscow – and after an explosive confrontation with Zelenskiy at the White House on Friday in which Trump criticized him for being insufficiently grateful for Washington’s backing in the war with Russia.

“President Trump has been clear that he is focused on peace. We need our partners to be committed to that goal as well. We are pausing and reviewing our aid to ensure that it is contributing to a solution,” said the official on Monday, speaking on the condition of anonymity.

The White House had no immediate comment on the scope and amount of aid affected or how long the pause would last. The Pentagon could not provide further details.

Zelenskiy’s office did not immediately respond to a Reuters request for comment nor did the Ukrainian Embassy in Washington.

On Monday, Trump again said Zelenskiy should be more appreciative of American support after earlier responding angrily to an Associated Press report quoting Zelenskiy as saying the end of the war is “very, very far away.”

“This is the worst statement that could have been made by Zelenskyy, and America will not put up with it for much longer!” Trump wrote on Truth Social, using an alternative spelling of the Ukrainian leader’s name.

Since Russia’s invasion three years ago, the U.S. Congress has approved $175 billion in total assistance for Ukraine, according to the nonpartisan Committee for a Responsible Federal Budget, read the report.

The Trump administration inherited $3.85 billion worth of Congressionally-approved authority to dip into U.S. arms stocks for Ukraine, but given the growing row between Washington and Kyiv, it was already unlikely for that assistance to be used.

Monday’s move goes beyond the no-new aid stance Trump had taken since assuming office – and appears to halt deliveries of military equipment approved by Biden including munitions, missiles and other systems.

But Trump also suggested on Monday that a deal to open up Ukraine’s minerals to U.S. investment could still be agreed despite his frustration with Kyiv, as European leaders floated proposals for a truce in Russia’s war with its neighbor.

The Trump administration views a minerals deal as America’s way of earning back some of the tens of billions of dollars it has given to Ukraine in financial and military aid since Russia invaded three years ago.

When asked on Monday if the deal was dead, Trump said at the White House: “No, I don’t think so.”

Trump described it as a “great deal for us” and said he would give an update on the situation on Tuesday night when he addresses a joint session of Congress.

In an interview on Fox News, Vice President JD Vance called on Zelenskiy to accept the minerals deal.

“If you want real security guarantees, if you want to actually ensure that Vladimir Putin does not invade Ukraine again, the very best security guarantee is to give Americans economic upside in the future of Ukraine,” Vance said.

Zelenskiy has made clear that a ceasefire must carry explicit security guarantees from the West to ensure that Russia, which holds about 20% of its land, does not attack again. Trump has refused to give any such guarantees, Reuters reported.

Beyond the military portion, U.S. assistance to Ukraine also includes budgetary assistance, largely delivered through a World Bank trust fund, and other funds that had been delivered through the U.S. Agency for International Development, which has been throttled by the Trump White House.

The U.S. decision left many questions unanswered, including whether munitions for the already delivered weapons systems can now be supplied or if the U.S. would still share intelligence with Ukraine on target identification and missile launches.

Key members of congressional oversight committees were not notified of the decision, including those on the Senate Armed Services Committee, a person with knowledge told Reuters.

Razom for Ukraine, a Ukrainian advocacy group, condemned the White House’s decision on aid. “By abruptly halting military assistance to Ukraine, President Trump is hanging Ukrainians out to dry and giving Russia the green light to keep marching west,” the group said in a statement.

Prior to the White House’s decision to halt its aid, European nations were rallying around Zelenskiy and trying to hatch a peace plan.

Privately, and sometimes publicly, officials are fuming at what they see as a betrayal of Ukraine, which had enjoyed staunch support from Washington since Russia’s invasion.

France, Britain and potentially other European countries have offered to send troops to Ukraine in the event of a ceasefire – something Moscow has already rejected – but say they would want support from the U.S., or a “backstop.”

“There are clearly a number of options on the table,” British Prime Minister Keir Starmer’s spokesman said.

Ukraine’s Volodymyr Zelenskiy said on Sunday he believed he could salvage his relationship with U.S. President Donald Trump after their explosive meeting in the Oval Office, but that talks needed to continue behind closed doors.

Zelenskiy reiterated that Ukraine would not concede any territory to Russia as part of a peace deal. He said he was still willing to sign a minerals deal with the U.S. and described a discussion on Sunday with European leaders to send a draft peace plan to the U.S. as a key development.

In an extraordinary meeting that was broadcast live on Friday, Trump accused Zelenskiy of being ungrateful for U.S. aid, of showing disrespect to his country and of risking World War Three, casting into doubt Washington’s ongoing support for Ukraine in its three-year-long war with Russia.

Zelenskiy spoke to reporters at a London airport after a summit with European leaders in London on Sunday. While he seemed in good spirits and thanked European countries for their support, the Ukrainian leader was careful to balance his dismay with the events of Friday’s Oval Office meeting with a clear desire to keep talking with Washington.

Zelenskiy said he did not think the U.S. would stop its assistance to Ukraine, because as “leaders of the civilized world” they would not want to help Russian President Vladimir Putin.

But he said he remained prepared for any outcome.

“As regards salvaging the relationship, I think our relationship will continue,” Zelenskiy told reporters via a translator after the London summit.

But he added: “I do not think it’s right when such discussions are totally open. … The format of what happened, I don’t think it brought something positive or additional to us as partners.”

A visibly shaken Zelenskiy arrived in London on Saturday where he was met with a warm embrace from British Prime Minister Keir Starmer and by cheering supporters around Downing Street.

At the summit on Sunday Starmer said European leaders had agreed to draw up a Ukraine peace plan to take to the U.S., in the hope that Washington would offer the security guarantees Kyiv says are vital to deter Russia.

Zelenskiy said Ukraine relied on the U.S. as its top military backer and that stopping the supply of weapons would only help Putin. “The U.S. are … leaders of the civilized world, and they will not help Putin,” he said.

An influential Russian parliamentarian, Konstantin Kosachev, on Sunday derided the hopes for Europe’s stepping up to forge a peace plan. “And if Ukraine should count on something, it can only be on progress (if there is any to come) in Russian-American relations,” he wrote on Telegram.

The abrupt ending to Zelenskiy’s Washington trip meant that the two countries failed to sign a much-vaunted minerals deal that Kyiv hoped would spur Trump to back Ukraine’s war effort, but Zelenskiy said Ukraine was still willing to sign it.

“We agreed upon signing it; and we were ready to sign it. And honestly I believe the United States would be ready as well,” he said.

Trump had sought to cast the minerals deal as a way for Ukraine, which is home to a trove of lithium deposits and rare earth minerals, to repay the U.S. for its billions of dollars in aid.

While Zelenskiy sought to avoid any further antagonism of the U.S., saying he did not want to go over what had happened, he was more forceful on any future ceasefire deal, saying Ukraine would not hand sovereignty of occupied Ukrainian land to Russia.

“Everyone needs to understand that Ukraine will never recognise whatever is occupied by Russia as Russian territories,” he said.

“We hope that these security guarantees will make it 100% impossible to give Russia the opportunity to come with another aggression”.

Zelenskiy said there had been contact between Kyiv and Washington since Friday’s bust-up, although not at his level, and asked if he had considered resigning, he showed no sign of wavering.

“As regards resignation, if I’m to be changed … to change me it will not be easy because it is not enough to simply hold elections. You would need to prevent me from participating in the elections and it will be a bit more difficult.”

Some Republican leaders had suggested that Zelenskiy needed to resign after Friday’s meeting with Trump.

Zelenskiy repeated again, however, that if Ukraine was granted NATO membership, he would have fulfilled his mission.

British Prime Minister Keir Starmer greeted President Volodymyr Zelenskiy with a warm embrace on Saturday after the Ukrainian leader flew to London for talks following his clash at the White House with U.S. President Donald Trump.

In an extraordinary Oval Office meeting on Friday, Trump threatened to withdraw support for Ukraine, three years after Russia invaded its smaller neighbour, Reuters reported.

French President Emmanuel Macron spoke to Zelenskiy and Trump on Saturday and called for calm in an interview following Friday’s White House clash.

In London, a crowd cheered as Zelenskiy arrived for talks with Starmer at his Downing Street office before a summit of European leaders that the Ukrainian president will attend on Sunday to discuss a peace plan for Ukraine.

“I hope you heard some of that cheering in the street. That is the people of the United Kingdom coming out to demonstrate how much they support you … and our absolute determination to stand with you,” Starmer told him.

Starmer told Zelenskiy he had “full backing across the United Kingdom.”

“We stand with you and Ukraine for as long as it may take,” Starmer said.

Zelenskiy said on Saturday he had “important and warm” talks with Starmer, with a discussion on strengthening Ukraine’s position and obtaining reliable security guarantees.

“During our talks we discussed the challenges standing before Ukraine and all of Europe, coordination with our partners, concrete steps to strengthen Ukraine’s position and ending the war in a just fashion, with reliable security guarantees,” Zelenskiy wrote on the Telegram messaging app.