Donald Trump has accused Volodymyr Zelensky of "not being ready for peace" in a blistering social media statement following the pair's Oval Office clash.

In a Truth Social post which has sent fears skyrocketing that a crucial minerals deal could be called off, Trump wrote: "We had a very meaningful meeting in the White House today.

"Much was learned that could never be understood without conversation under such fire and pressure.

"It's amazing what comes out through emotion, and I have determined that President Zelensky is not ready for peace if America is involved, because he feels our involvement gives him a big advantage in negotiations.

The spat could leave a vital US-Ukraine minerals deal in jeopardy

"I don't want advantage, I want PEACE.

"He disrespected the United States of America in its cherished Oval Office. He can come back when he is ready for peace."

Minutes later, US media reported that a press conference between the two Presidents was cancelled, and the Ukrainian delegation was on its way out of the White House.

A UK Government source told Sky News the Oval Office spat was "unhelpful".

A UK Government source told Sky News the Oval Office spat was 'unhelpful'

"Zelensky is no diplomat," they said. "Trump was egged on by Vance, and then got a full belligerent performance.

"Hopefully they'll cool off and we get a deal and a press conference. But [there's a] risk it's all off."