WINDOW ROCK, Ariz. (AP) — Jerry C. Begay Sr., a Navajo code talker who helped confound the Japanese during World War II and was awarded a Congressional Silver Medal, died Monday. He was 83.

Begay died in Albuquerque, N.M., the Navajo Nation Council said. No cause of death was given.

The code talkers were an elite group of Navajo Marines who transmitted radio messages during the war in a coded version of their native language. The codes were never cracked by enemy forces; the talkers' existence was a military secret for decades after the war ended.

Begay served in Tarawa during the U.S. invasion of the Japanese island and was honorably discharged in 1945.

He was active in the Navajo Code Talkers Association and received the Congressional Silver Medal in 2001.