DJI drones may be banned from being sold in the US for not having required government security reviews before a looming deadline.

In a bid to avert the ban, the China drone maker has written to five US national security agencies pleading with them to hold the security reviews. If not, in less than three weeks, the drones may lose access to radio frequencies essential to flying and transmitting flight data such as video.

Fellow China drone maker Autel Robotics is in a similar predicament.

The drone makers risk being added to the Federal Communications Commission’s “Covered List” and be subject of a national sales ban.

“Being placed on the FCC Covered List has significant operational consequences,” Drone Life reports. “The designation identifies communications and camera equipment deemed to pose national security risks. Importantly for drone systems, Covered List status affects access to FCC-authorized radio frequencies used for command-and-control links and video transmission.”

“They could lose the ability to operate legally on certain federally regulated radio bands in the United States. This could restrict or prevent operation of many future or current DJI models, particularly in professional and enterprise contexts where FCC-authorized spectrum is required for reliable links.

“The result may be a practical ban on the use of many DJI aircraft in government-funded programs, public safety agencies, and industry sectors reliant on FCC-compliant operations.”

DJI told Nikkei Asia that its offers to work with the federal agencies have gone unanswered, but it remains open to cooperating with them.

“It is hoping for an immediate audit to avoid being added to the telecom regulator’s blacklist of companies not allowed to import or sell new equipment. The ban would bar only new DJI products from receiving an FCC license to fly; existing products would not be affected,” it says.

DJI says a ban would lead to widespread consumer confusion and deprive American drone users of due process — and of answers about the safety and security of the DJI products they use every day. “Failing to undertake the review further goes against Congressional intent for a security review to be completed.”

The letters, signed by DJI’s Head of Global Policy Adam Welsh, were sent to the Department of Homeland Security, Department of Defense, the FBI, National Security Agency and the Office of the Director of National Intelligence, Nikkei Asia says.

DJI says Homeland Security had committed to a review in September. It told Nikkei Asia it made several attempts earlier in the year to set up meetings with five national security agencies, but there has been no formal response.

Nine out of 10 drones used by US public safety agencies are made by DJI, Bard College research found, the publication says.