U.S. intelligence agencies warned private American space companies on Friday that foreign intelligence agencies are targeting the industry in efforts to steal or undermine critical technologies.

The National Counterintelligence and Security Center, the FBI and the Air Force’s Office of Special Investigations, urged the industry to beware of various efforts by foreign entities to gain access to information, including through joint ventures, acquisitions, facility visits and employee recruitment.

“Foreign intelligence entities (FIEs) recognize the importance of the commercial space industry to the US economy and national security, including the growing dependence of critical infrastructure on space-based assets,” the agencies said in Friday’s bulletin.

“They see US space-related innovation and assets as potential threats as well as valuable opportunities to acquire vital technologies and expertise,” they added.

While the bulletin did not specify any particular countries, an American counterintelligence official told Reuters that China and Russia are “among the leading foreign intelligence threats” to the industry.

The trio of agencies encouraged U.S. space companies on Friday to track peculiar incidents, establish insider threat programs, conduct due diligence on suppliers and investors, and incorporate security requirements into contracts with third parties, among other mitigation efforts.