WASHINGTON/OSLO - US President Donald Trump said on Thursday that he will sign a rare earth minerals deal with Ukraine "very shortly".

"We are doing good work with Ukraine and Russia. And one of the things we are doing is signing a deal very shortly with respect to rare earth with Ukraine," the president said.

Trump made the remarks shortly after he signed an executive order to invoke emergency powers to "dramatically increase production of critical minerals and rare earths."

"We're also signing agreements in various locations to unlock rare earths and minerals and lots of other things all over the world, but in particular Ukraine," Trump said.

He said last month that he asked Ukraine to provide the United States rare earth worth $500 billion.

"I told them [Ukraine] that I want the equivalent like $500b worth of rare earth. And they've essentially agreed to do that so at least we don't feel stupid," Trump said in an interview with Fox News at the time.

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Trump and Ukrainian President Volodymyr Zelensky were scheduled to sign a deal at the end of February in Washington that would grant Washington access to Ukraine's mineral deposits.

However, the deal remained unsigned after Zelensky's meeting in the Oval Office with Trump and his deputy JD Vance turned into a heated exchange. 

Meanwhile, Trump announced on Thursday that he had signed an executive order to enhance domestic production of critical minerals and rare earths.

"The United States was once the world's largest producer of lucrative minerals, but overbearing federal regulation has eroded our nation's mineral production," Trump said in the order.

The order leverages the Defense Production Act (DPA) to provide financing, loans and other investment support for domestic mineral processing.

It also directs federal agencies to identify mines that can be quickly approved and federal lands, including those controlled by the Pentagon, that could be used for minerals processing.

Also on Thursday, Zelensky reaffirmed Ukraine's commitment to diplomatic talks with the United States while expressing skepticism about Russia's willingness to agree to a ceasefire.

During his visit to Oslo, Zelensky confirmed that Ukrainian and Russian representatives will meet their American counterparts respectively in Saudi Arabia on Monday for discussions on Ukraine's future.