Talks between Ukrainian President Volodymyr Zelenskiy and U.S. Vice President JD Vance ended in Munich on Friday without an announcement of a critical minerals deal that is central to Kyiv's push to win the backing of President Donald Trump.

Kyiv came back to the U.S. earlier with a revised draft agreement of the deal that could open up its vast resources of key minerals to U.S. investment, amid concerns in Kyiv over a U.S. version that was presented to Ukraine on Wednesday.

"Our teams will continue to work on the document," Zelenskiy wrote on X, adding that he had had a "good meeting" with Vance and that Kyiv was "ready to move towards as quickly as possible towards a real and guaranteed peace".

Two members of the Ukrainian delegation told Reuters that "some details" still needed to be worked out.

It was not immediately clear what the sticking point was, but Ukraine is pressing for robust security guarantees from Europe and the United States that would protect it from Russia in the future if a peace deal is reached.

Zelenskiy set out the contours of the deal in a Reuters interview last week, unfurling a map showing numerous mineral deposits and saying he was offering a mutually beneficial partnership to develop them jointly and not "giving them away".

The minerals in question would include rare earth varieties, as well as titanium, uranium and lithium among others.

Trump, who has not committed to continuing vital military assistance to Ukraine, has said he wants $500 billion in rare earth minerals from Kyiv and that Washington's support needs to be "secured".

Asked earlier if there would be a deal agreed on Friday, Vance had said: "Let's see."

Ukraine was presented with a draft accord drawn up by the United States on Wednesday when Treasury Secretary Scott Bessent travelled to Kyiv. Zelenskiy said Ukraine would study it with a view to reaching an agreement in Munich.

Bessent told Fox Business Network on Friday that the Trump administration's plan to end the war would intertwine Kyiv's economy with the United States, with the U.S. bringing its "best practices" of privatization.

He said: "Part of it starts with intertwining the ... Ukrainian economy more with the U.S., and making sure that U.S. taxpayers receive the return for the money they put in."

'ONE-SIDED' OFFER?

Meeting for 90 minutes with a bipartisan group of U.S. senators behind closed doors in Munich, Zelenskiy voiced concern about the U.S. proposal presented on Wednesday, three sources familiar with his presentation said.

He "felt he was being asked unreasonably to sign something he hadn't had a chance to read", one of them said on condition of anonymity. "I don't think he appreciated being given a take-it-or-leave-it thing."

Zelenskiy discussed his own proposal for a mineral deal with the United States, the source said, saying it was drafted to comply with the Ukrainian constitution.

Two other sources characterized the proposal delivered by Bessent as "one-sided", but declined to elaborate.

Democratic Senator Brian Schatz, asked after the meeting if Zelenskiy considered the U.S. proposal one-sided, responded, "I think that's fair to say."

Schatz said that the Trump proposal "needs massaging," but declined to go into detail.