Ukraine's Volodymyr Zelenskyy said on Sunday he believed he could salvage his relationship with US President Donald Trump after their explosive meeting in the Oval Office, but that talks needed to continue behind closed doors, Reuters reports.

Speaking to reporters after a summit with European leaders in London, Zelenskyy said he did not think the US 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," Zelenskyy told reporters. "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."

Zelenskyy said he was still willing to sign a minerals deal with the US. According to the Ukrainian leader, the US would also be prepared for it.