Federal officials are acknowledging widespread drone access to U.S. skies faces significant hurdles and will take longer than Congress expected.

The Federal Aviation Administration says it’s developed a “roadmap” for integrating unmanned aircraft safely into the national airspace.

A statement from the FAA doesn’t address privacy, one of the most widespread concerns associated with drones, except for drone use at six test sites not yet chosen.

The statement says that for the next several years drone access will be limited to permits the FAA grants on a case-by-case basis to operators who agree to procedures to reduce safety risks.

Last year, Congress directed the FAA to grant drones widespread access by September 2015. The agency has missed several deadlines for steps need to make that happen.

(AP)