A Ukrainian official was on the way to Washington for the signing. But a source said the U.S. was pushing Ukraine to sign two additional documents and that Kyiv felt it was premature.

Bessent denied the U.S. made any attempt to change the accord the two sides agreed to over the weekend.

The agreement, which would give the United States access to Ukraine’s minerals deposits, is central to Kyiv’s efforts to mend ties with U.S. President Donald Trump and the White House as Trump tries to secure a peace settlement in Russia’s war in Ukraine.

Two sources told Reuters the signing could happen later on Wednesday. Ukraine’s First Deputy Prime Minister Yulia Svyrydenko was flying to the United States to sign the deal, the country’s prime minister said earlier.