NEW YORK (AP) — Federal prosecutors have charged a cryptocurrency expert with violating economic sanctions against North Korea by presenting at a conference there this year after the U.S. government denied his request to travel to Pyongyang.

Virgil Griffith, 36, was awaiting a federal court appearance Friday in Los Angeles, a day after he was arrested at Los Angeles International Airport.

Griffith is an American citizen but lives in Singapore. Messages were sent to Griffith's defense attorney seeking comment.

Federal prosecutors said Griffith secured a visa through "a (North Korean) diplomatic...