Three sources familiar with the matter have told Reuters Ukraine's continued access to SpaceX-owned Starlink was brought up in discussions between US and Ukrainian officials after Ukrainian President Volodymyr Zelenskiy turned down an initial proposal from US Treasury Secretary Scott Bessent.
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 US 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 $US500 billion ($A787 billion) in mineral wealth from Ukraine to repay Washington for wartime aid, saying the US has offered no specific security guarantees.
On Friday, the Ukrainian president said the US 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.
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 US 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 US 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.
Trump has embraced the idea, saying he wants Ukraine to supply the US with rare earths and other minerals in return for financially supporting its war effort.
Zelenskiy rejected a detailed US proposal last week that would have seen Washington and US firms receiving 50 per cent of Ukraine's critical minerals, which include graphite, uranium, titanium and lithium, a key component in electric car batteries.
