Elon Musk, chief executive officer of Space Exploration Technologies Corp. (SpaceX) and Tesla Inc., speaks during an event at SpaceX headquarters in Hawthorne, California, U.S., on Thursday, Oct. 10, 2019.

Elon Musk's rocket company SpaceX has banned its employees from using video conferencing app Zoom, citing "significant privacy and security concerns," according to a memo seen by Reuters, days after U.S. law enforcement warned users about the security of the popular app.

Use of Zoom and other digital communications has soared as many Americans have been ordered to stay home to slow the spread of coronavirus.

SpaceX's ban on Zoom Video Communications Inc illustrates the mounting challenges facing aerospace manufacturers as they develop technology deemed vital to national security while also trying to keep employees safe from the fast-spreading respiratory illness.

In an email dated March 28, SpaceX told employees that all access to Zoom had been disabled with immediate effect.

"We understand that many of us were using this tool for conferences and meeting support," SpaceX said in the message. "Please use email, text or phone as alternate means of communication."

Two people familiar with the matter confirmed the contents of the mail.