U.S. negotiators pressing Kyiv for access to Ukraine's critical minerals have raised the possibility of cutting the country's access to Elon Musk's vital Starlink satellite internet system, three sources familiar with the matter told Reuters.

Ukraine's continued access to SpaceX-owned Starlink was brought up in discussions between U.S. and Ukrainian officials after Ukrainian President Volodymyr Zelenskiy turned down an initial proposal from U.S. Treasury Secretary Scott Bessent, the sources said.

Starlink provides crucial internet connectivity to war-torn Ukraine and its military.

The issue was raised again on Thursday during meetings between Keith Kellogg, the U.S. special Ukraine envoy, and Zelenskiy, said one of the sources, who was briefed on the talks.

During the meeting, Ukraine was told it faced imminent shutoff of the service if it did not reach a deal on critical minerals, said the source, who requested anonymity to discuss closed negotiations.

"Ukraine runs on Starlink. They consider it their North Star," said the source. "Losing Starlink ... would be a massive blow."

After Reuters published its story, Musk posted on X that the article was “false” and “Reuters is lying.” Contacted by Reuters for specifics, Musk did not immediately respond.

A Reuters spokesperson said the news agency stands by its reporting.

Zelenskiy has rejected demands from President Donald Trump's administration for $500 billion in mineral wealth from Ukraine to repay Washington for wartime aid, saying the U.S. has offered no specific security guarantees.

On Friday, the Ukrainian president said the U.S. and Ukrainian teams were working on an agreement and Trump said he expects a deal will be signed soon.

Musk rushed thousands of Starlink terminals to Ukraine to replace communications services destroyed by Russia after its February 2022 invasion. Hailed at the time as a hero in Ukraine, Musk later curtailed access at least once before in the fall of 2022 as he became more critical of Kyiv's handling of the war.

Poland's deputy prime minister said on Saturday that his country has been paying for Ukraine's Starlink subscription and will continue to do so.

U.S. lawmakers are divided over Trump's efforts to find a quick end to the Ukraine war and some have raised questions about Musk's rapid-fire efforts to cull thousands of federal workers and shut down Federal agencies.

Melinda Haring, a senior fellow with the Atlantic Council, said Starlink was essential for Ukraine’s operation of drones, a key pillar of its military strategy.

“Losing Starlink would be a game changer,” Haring said, noting that Ukraine was now at 1:1 parity with Russia in terms of drone usage and artillery shells. Ukraine has a wide range of different drone capabilities, ranging from sea drones and surveillance drones to long-range unmanned aerial vehicles.

The Ukrainian embassy in Washington, the White House and the U.S. Department of Defense did not respond to a request for comment.

SpaceX, which operates Starlink, also did not respond to a request for comment.

Russian and U.S. negotiators have planned a second meeting in the coming two weeks to discuss ending the conflict, Russia's RIA state news agency reported on Saturday. The first meeting took place in Riyadh on Tuesday.

Last fall, Ukraine floated the idea of opening its critical minerals to investment by allies. This was part of a "victory plan" that sought to put it in the strongest position for talks and force Moscow to the table.

Trump has embraced the idea, saying he wants Ukraine to supply the U.S. with rare earths and other minerals in return for financially supporting its war effort.

Zelenskiy rejected a detailed U.S. proposal last week that would have seen Washington and U.S. firms receiving 50% of Ukraine's critical minerals, which include graphite, uranium, titanium and lithium, a key component in electric car batteries.

Since then a rift has emerged between the leaders, with Trump denouncing Zelenskiy as "a dictator without elections" on Wednesday after Zelenskiy said Trump was trapped in a Russian disinformation bubble, a response to the U.S. president suggesting Ukraine started the war.