WASHINGTON -- US President Donald Trump said Tuesday he's "OK" with a possible visit to Washington by Ukrainian President Volodymyr Zelensky, during which the two presidents are set to sign a deal that gives the United States a cut of Ukraine's mineral wealth.

"I hear that he's coming on Friday. Certainly, it's OK with me if he'd like to. And he would like to sign it together with me. And I understand that's a big deal, very big deal," said Trump when speaking to reporters in the Oval Office.

"It could be a trillion-dollar deal. It could be whatever, but it's rare earths and other things," Trump said.

According to US media reports, Ukraine agreed to the final version of the draft deal that the United States proposed Tuesday.

With the exact terms of the final deal still unclear, the draft discussed Tuesday included the establishment of a fund to be jointly owned by Ukraine and the United States, to which Ukraine will contribute 50 percent of its revenues from the future monetization of natural resources, including critical minerals, oil and gas, according to reports by US media.

The United States would own the maximum financial interest in the fund allowed under American law, The New York Times said in a report, adding that the fund would be designed to reinvest some revenues into Ukraine, and the United States would also commit to supporting Ukraine's future economic development.

The latest draft deal no longer includes the demand that Ukraine contribute 500 billion US dollars to a fund owned by the United States and the request that Ukraine pay back the United States twice the amount on any future American aid, The New York Times said.

The issue of Washington providing security guarantees to Kiev, a key request from Ukraine, was not in the deal, according to US media reports, which said the issue would be discussed between Trump and Zelensky when the latter arrives in Washington.