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.