U.S. negotiators have reportedly pressed Ukraine for access to its critical minerals, warning that the country could face a shutdown of the vital Starlink satellite internet system, three sources familiar with the matter told Reuters.

According to sources, discussions on Ukraine’s access to SpaceX-owned Starlink were raised after Ukrainian President Volodymyr Zelenskiy turned down an initial proposal from U.S. Treasury Secretary Scott Bessent. The matter came up again during a recent meeting between U.S. Special Ukraine Envoy Keith Kellogg and Zelenskiy, with Ukraine allegedly being warned of an imminent service cut-off if a deal on critical minerals was not reached.

Starlink provides crucial internet connectivity in Ukraine, particularly for military operations. Experts warn that losing access to the system would significantly impact Ukraine’s ability to operate drones and maintain battlefield communications. Melinda Haring, a senior fellow at the Atlantic Council, described Starlink as essential, noting that Ukraine’s drone capabilities are currently on par with Russia.

Ukraine had previously considered opening its critical mineral resources to investment by allied nations as part of a strategy to strengthen its position in negotiations with Moscow. However, last week, Zelenskiy rejected a U.S. proposal that would have granted Washington and American companies 50% of Ukraine’s reserves, which include key materials like lithium, titanium, graphite, and uranium.

Following the rejection, tensions have escalated between the two leaders. Former U.S. President Donald Trump criticized Zelenskiy, calling him “a dictator without elections,” while Zelenskiy responded by accusing Trump of falling for Russian disinformation.

Neither the Ukrainian embassy in Washington nor U.S. officials, including the White House and the Department of Defense, have commented on the ongoing negotiations. SpaceX, which operates Starlink, has also not issued a response.