On March 17, Gen. Mark Milley, the chair of the U.S. Joint Chiefs of Staff, and Gen. Valeriy Zaluzhnyi, the leader of Ukraine’s armed forces, dialed into a call to discuss Russia’s invasion of Ukraine. Over the secure line, the two military leaders conferred on air defense systems, real-time battlefield assessments and shared intelligence on Russia’s military losses.

They also talked about Elon Musk.

Zaluzhnyi raised the topic of Starlink, the satellite internet technology made by Musk’s rocket company, SpaceX, three people with knowledge of the conversation said. Ukraine’s battlefield decisions depended on the continued use of Starlink for communications, Zaluzhnyi said, and his country wanted to ensure access and discuss how to cover the cost of the service.