MINNEAPOLIS — Retired Army Gen. John W. Vessey Jr., who rose through the ranks in a 46-year military career to become chairman of the Joint Chiefs of Staff and help oversee President Reagan’s military buildup, has died. He was 94.

Vessey enlisted as a private in the Minnesota National Guard in 1939, fought in World War II and Vietnam, and was the nation’s top military officer when he retired to his home state of Minnesota in 1985. He died of natural causes Thursday evening surrounded by family, said his daughter, Sarah Vessey.

After being named chairman of the Joint Chiefs in 1982, Vessey helped oversee the military expansion that Reagan championed when he took office just over a year earlier.

“It was probably the greatest peacetime modernization of the American military establishment that ever took place,” Vessey recalled in a 2004 interview. “We improved every facet of the armed forces, from the recruiting and retention, the selection of individuals, to the way they lived, but most importantly to the way they fought.”

Vessey said the Soviet Union had been making a “big push” to solidify its position in Europe, deploying SS20 intermediate-range nuclear missiles and strengthening its ground forces in East Germany, “dabbling” in West European elections at a time when NATO was shaky, and stepping up its espionage.

By the time Vessey retired in 1985, he said, NATO was strong once again, the United States had deployed Pershing II and cruise missiles in response to the Soviet SS20s, and negotiations with the Soviets to eliminate each side’s intermediate-range missiles were just about complete.

“He was smart and combined good common sense with good military judgment, and he knew how to get things done,” Lawrence Korb, a senior fellow at the Center for American Progress, a Washington think tank, said in a 2006 interview. Korb worked with Vessey while serving as an assistant secretary of defense from 1981 to 1985.

Reagan sent Vessey back to Vietnam in 1987 to account for Americans missing in action and bring back any still alive. His other tasks included reuniting separated families and getting former South Vietnamese leaders out of prison camps, Amerasian children out of Vietnam and the Vietnamese out of Cambodia.