WASHINGTON (AP) — The director of national intelligence is disputing allegations that he lied to Congress about a surveillance program last year.

James Clapper is rolling out a new national intelligence strategy that includes principles of ethics for intelligence officers.

Clapper says it has been very disappointing to have his integrity questioned “because of a mistake.” He was speaking Thursday to intelligence contractors in a ballroom at a Washington intelligence summit.

Clapper says he misspoke when he denied in a Senate hearing last year that the U.S. was collecting data on millions of Americans. Leaks by former NSA contractor Edward Snowden showed the National Security Agency had been collecting American phone records under a program that President Barrack Obama is trying to discontinue.