Starlink satellite internet terminals, created by Ilon Musk's SpaceX, have become a vital source of communication for the Ukrainian military. To date, about 20,000 Starlink satellites have been handed over to Ukraine. However, Musk tweeted Friday that "the operation cost SpaceX $80 million and will exceed $100 million by the end of the year."

But those charitable donations could be coming to an end, as SpaceX warned the Pentagon that it could cut off funding for the satellite service in Ukraine unless the U.S. military committed tens of millions of dollars a month.

According to CNN, citing documents, Musk's SpaceX sent a letter to the Pentagon last month stating that it could no longer continue to fund the Starlink service as it used to. The letter also asked the Pentagon to take over the funding, which SpaceX claims will cost more than $120 million by the end of the year and about $400 million more over the next 12 months.

Among the documents SpaceX sent to the Pentagon and, there is a direct request made to Musk in July by Ukrainian commander Gen. Valery Zaluzhny for nearly 8,000 more Starlink terminals.