Both the United States and Ukraine say they have extensively prepared to sign an agreement that will allow U.S. companies to use Ukrainian minerals.

"We are ready to sign this afternoon," Treasury Secretary Scott Bessent said Wednesday, adding that Ukraine "decided to make last-minute changes to the agreement."

Ukrainian Deputy Prime Minister Yulia Svyrydenko flew to Washington on Wednesday after a clear breakthrough in negotiations.

Earlier, the BBC News saw a draft deal that stipulated the creation of the Ukrainian-US Investment Fund to find Ukrainian-US Investment Fund and determine how to distribute income.

On Wednesday afternoon, a U.S. source familiar with the negotiations criticized Ukraine for trying to reopen some terms that had been agreed over the weekend.

Sources told the BBC that the U.S. and Ukraine teams were all night long to finalize the documents and completed early Wednesday morning.

The sticky points include the governance of the fund, the transparency mechanism and the steps to ensure that all funds are fully traceable.

Despite last-minute negotiations, the signing could still be held at the end of Wednesday if the U.S. side believes Ukraine is complying with the terms already reached.

"No removals were made," Best said when asked about any changes to the deal. "This is the consent we agreed on the weekend. There was no change on our side."

The technical documents were signed by representatives of the two countries last week.

In Kiev, Prime Minister Denys Shmyhal said Ukraine expects the deal to be signed "in the next 24 hours."

"This is indeed a good, equal and beneficial international agreement on Ukraine's development and recovery of co-investment," Shyhal said.

Since returning to the White House, U.S. President Donald Trump has repeatedly pushed for a deal as a prerequisite for any future security assurance to Kiev, as Ukraine continues to fight invading Russian forces.

Ukraine is believed to have a large number of key rare minerals under its soils, such as graphite, titanium and lithium. They are highly sought after due to their use in renewable energy, military applications and industrial infrastructure.

The Trump administration has pushed opportunities to enter another country's mineral wealth amid the evolving trade war with China, where 90% of the world's stocks are currently coming from.

The deal in the draft also appears to have given the U.S. scoped opportunities in Ukrainian industries beyond minerals.

While it does not specify the security support that Washington is willing to provide, it notes that the deal is “a tangible testament to the United States of America’s support for Ukraine’s security.”

The deal comes days after a face-to-face meeting between Trump and Ukrainian President Volodymyr Zelensky at the funeral of Pope Francis, as negotiations between Moscow and Washington continue in Ukraine’s possible ceasefire.

The latest Trump-Zelensky negotiations appear to be more friendly than the meeting at the White House in February and resulted in a softer tone from the U.S. president to his Ukrainian opposition in the days that followed, and increased levels of criticism of the Russian attack.

"As you know, we're always looking for rare earths (minerals).

"They have a lot of things and we have an agreement so we can start digging and doing what we have to do. It's good for them, too."

The initial deal was scheduled to be signed in February, but after a fierce exchange between the two leaders, Trump accused Zelensky of “gambling with World War III.”