WASHINGTON — FBI Director James Comey is again warning about the bureau’s inability to access digital devices because of encryption.

In a speech Tuesday, Comey said default encryption built into smartphones is “making more and more of the room that we are charged to investigate dark.”

He said the FBI is working to collect information on the issue so that “next year we can have an adult conversation in this country.”

He said that while Americans have a reasonable expectation of privacy in houses, cars and electronic devices, law enforcement officials can “invade our private spaces” with legal approval. Comey said that “bargain” has been part of the country since its founding.

Comey spoke at a symposium organized by Symantec, a software technology company.