Ukraine’s fears deepened in the past week that its forces may lose access to Elon Musk’s Starlink internet service after 1,300 of the military’s satellite units went offline, according to two sources familiar with the matter cited by CNN.

The satellite dishes made by Musk’s SpaceX have been globally hailed as a game-changing communication source for Ukraine’s military, allowing it to fight and stay online even as cell phones and internet have been destroyed in the Ukraine war. 

However, the dependability of SpaceX after funding discussions was revealed and outages were reported near the frontlines caused concerns to rise.

CNN first reported that in September, SpaceX sent a letter to the Pentagon claiming it had spent nearly $100 million on the funding of Starlink in Ukraine and that it could no longer keep doing it. The letter demanded the Defense Department to take over more of the funding for Ukraine’s military, which it assessed would run at a cost of tens of millions of dollars per month. 

Days later, Musk announced that SpaceX will continue to fund Starlink in Ukraine for free, doing a 180 after saying that he cannot keep funding the project.

Read: Musk now says will continue funding Starlink in Ukraine

“The hell with it,” Musk tweeted, “we’ll just keep funding Ukraine govt for free.”

Despite Musk’s claim that SpaceX withdrew its request, the negotiations continued between the Defense Department and SpaceX, according to a senior defense official.

Musk attended on Wednesday a ceremony for the US Space Force which also included Secretary of Defense Lloyd Austin and the Chairman of the Joint Chiefs of Staff General Mark Milley. The world's richest man has been embroiled in his controversial acquisition of Twitter.

Read: Elon Musk claims to want to "help humanity" by buying Twitter

When asked to comment, none of Musk nor SpaceX responded. Also, the Ukrainian government, including the Defense Ministry, did not immediately respond.

The recent outage began on October 24 and was described as a “huge problem” for Ukraine’s military. Due to a lack of funding, the terminals had been disconnected.  

A block of 1,300 terminals was affected. The block was bought in March by Ukraine from a British company and was used for combat-related operations. 

Ukraine’s military was charged by SpaceX $2,500 a month to keep each of the 1,300 terminals connected, pushing the total to nearly $20 million by September, a person briefed on the matter reported. Eventually, they couldn't be able to afford it, the person said.