Yukio Kawamoto, a Japanese American who served as a U.S. Army combat intelligence specialist and interpreter in the Pacific during World War II, even as his parents were interned in a detention camp for ethnic Japanese living in America, died Jan. 7 at his home in Springfield, Va. He was 99.

The cause was congestive heart failure, said a son, Brian Kawamoto.

Fluent in Japanese, Mr. Kawamoto interrogated enemy prisoners of war on islands of the South Pacific, tried to persuade Japanese soldiers trapped in partially sunken ships or holed up in fortified caves to surrender, and translated captured enemy documents and personal letters found on the bodies of Japanese soldiers killed in battle, according to oral histories compiled by the National World War II Museum in New Orleans.

“On New Guinea, Kawamoto interviewed a Japanese deserter and learned of an imminent attack, allowing American troops to obtain reinforcements and prepare for the onslaught. Kawamoto also went to the Philippines and served in the Battle of Manila,” The Washington Post reported in 2011, the year Mr. Kawamoto received a Congressional Gold Medal for his wartime service.

Meanwhile, his parents, Kumajiro and Chisato Kawamoto, spent the war years confined in a Utah internment camp surrounded by a barbed-wire fence, under the eyes of armed guards stationed in watchtowers.

They were natives of Hiroshima, Japan, who had come to the United States about 25 years before World War II and settled in Berkeley, Calif. She had been a teacher of Japanese at a Buddhist temple. He earned a living from blue-collar odd jobs.

Two months after their son was drafted into the Army in February 1942, the elder Kawamotos were taken in a presidentially ordered roundup of 120,000 ethnic Japanese considered security risks and forcibly relocated to remote camps.

In 2011, Mr. Kawamoto told The Post that he took his own conscription into the Army as a wartime necessity and that his parents’ incarceration was beyond his control. He would visit them while on leave.

“I wasn’t happy about it,” he said. “They were there for the duration of the war, while I was out fighting for the United States. But what could you do?”

Yukio Kawamoto was born in Berkeley on Nov. 13, 1919. Japanese was the language spoken at home, but English became his primary language as he attended Berkeley public schools.

In the Army during World War II, he was sent to a Japanese-language school to test his fluency and receive additional training in Japanese. Then he was assigned as an interpreter to combat units in the Pacific.

In spring 1945, a few months before the war ended, the U.S. government began closing the internment camps where ethnic Japanese had been detained. Detainees were given $25 each and a train ticket home.

Mr. Kawamoto received an early discharge from military duties to help the detainees readjust to civilian life. He helped his parents resettle in Berkeley.

Later, he was a State Department interpreter in Washington. In 1963, he was the White House interpreter for a speech by President John F. Kennedy to a visiting delegation of Japanese officials.

He was an interpreter at the U.S. Embassy in Tokyo from 1975 to 1979, when he retired from federal service and settled permanently in the Washington area. He was one of the founders of the Ekoji Buddhist Temple in Fairfax Station, Va.

In 1947, he married Sayoko Omori, who was born in Japan. They met while he was an interpreter at war crimes tribunals in Tokyo. In addition to his wife, of Springfield, survivors include three children, Brian Kawamoto of Leawood, Kan., Don Kawamoto of Springfield and Sherin Ferguson of Mechanicsville, Va.; 11 grandchildren; and seven great-grandchildren. A son, Craig Kawamoto, died in 2018.

In February 1942, Mr. Kawamoto was in his last year at the University of California when he was drafted. Sixty-seven years later, he received his degree in a special UC ceremony — complete with caps and gowns and an academic procession for hundreds of former students whose college years had been interrupted by the war or internment.

On the home front during World War II, U.S. families who had a son, daughter, father or mother serving in the armed forces were given windowpane-size pennants with a single blue star for every family member serving. These were considered household badges of honor and were displayed prominently.

In a window of their quarters at Camp Topaz, Utah, the Kawamotos posted a one-star pennant for their son, Yukio.