News that Mr. Musk did not allow the use of his Starlink satellite network highlights concerns in Kyiv and Washington about his outsize influence in the war.
The Starlink satellite internet service, which is operated by Mr. Musk’s rocket company SpaceX, has been a digital lifeline for soldiers and civilians in Ukraine.
U.S. officials say Chinese and Russian spy agencies are trying to steal technology from private American space companies and preparing cyberattacks that could disable satellites in a conflict.
Small, fast-moving U.S. tech firms are using the war in Ukraine to demonstrate a new generation of military systems but face the challenge of selling them to a risk-averse Defense Department.