Lester L. Wolff, an eight-term congressman who championed Great Society legislation, helped to strengthen the United States’ military and cultural bond with Taiwan and later leveraged his experience in Asian affairs to work as a lobbyist for Myanmar’s repressive military government, died May 11 at a hospital in Syosset, N.Y. He was 102.

His son, Bruce Wolff, confirmed the death but did not provide a cause.

Mr. Wolff, a New York Democrat who represented parts of Queens and the Gold Coast of Long Island, was the oldest living veteran of Congress. Born at the close of World War I, he came to prominence as a marketing executive and the mustached host of a public-affairs television show in the 1950s.

Decades later, he switched platforms for YouTube and Twitter, where he railed against President Donald Trump (“he must think misogyny is another entrant in his Miss Universe contest”) and called for continued American support of Taiwan’s military.

Elected in the 1964 landslide that gave President Lyndon B. Johnson a full term in office, Mr. Wolff cast some of his first votes for the creation of Medicare and Medicaid. He later sponsored bills that increased public education funding and became known as one of the most travel-happy representatives in Congress.

He reportedly paid for five fact-finding trips to Vietnam out of his own pocket and in the mid-1960s appealed to Johnson and Vice President Hubert Humphrey — who lived in the same Washington apartment building as Mr. Wolff — to end the U.S. military involvement in that country, believing a U.S.-backed solution to the war there was out of reach.

As the founding chairman of the Select Committee on Narcotics Abuse and Control, which he helped to create in 1976, he aimed to halt drug smuggling into the United States, visiting each legal crossing point on the U.S.-Mexico border and traveling to centers of opium cultivation and heroin trafficking in South America and Asia.

Mr. Wolff served briefly as a U.S. delegate to the United Nations — a surprise, given his previous criticism of the organization for a vote it took to condemn Zionism — and said a high point of his career was adding an amendment to 1968 foreign aid legislation that urged Johnson to negotiate with Israel on the sale of new supersonic fighter-bombers.

Still, he remained best known for his work as chairman of the Asia and Pacific affairs subcommittee. Leading congressional delegations to China in the mid-1970s, he discussed the country’s political purity with the mayor of Shanghai — “What is wrong with brainwashing?” he said the mayor told him. “We wash our hands, we wash our face. Why not brains?” — and held pivotal meetings with Communist Party leader Deng Xiao­ping in 1978.

The talks, which centered on the disputed island of Taiwan, paved the way for the Carter administration’s decision to formally recognize the People’s Republic of China and withdraw recognition from Taiwan the following year, according to State Department documents cited by investigative reporter Jack Anderson.

The United States had not previously recognized the communist Chinese government, siding instead with the nationalist faction that fled to Taiwan at the close of the Chinese civil war. In an effort to maintain cultural and military ties with Taiwan, Mr. Wolff — along with Sens. Edward M. Kennedy (D-Mass.) and Alan Cranston (D-Calif.) — crafted what became the Taiwan Relations Act, which was passed in 1979 and established a quasi-diplomatic link between the two countries.

Mr. Wolff played a small role in the 1970s scandal known as Koreagate, in which South Korea’s intelligence agency was found to have staged an elaborate congressional lobbying campaign, throwing lavish parties for visiting congressmen in Seoul and allegedly arranging for the Korean rice trader Tongsun Park to deliver cash-filled envelopes to congressmen and their wives.

Three congressmen were formally reprimanded, and one, Rep. Richard T. Hanna (D-Calif.), was imprisoned after pleading guilty to a conspiracy charge. Mr. Wolff was never accused of impropriety, but his former aide Suzi Park Thomson became a leading figure in investigations of the scandal. She was linked to the Korean intelligence agency and traveled with Mr. Wolff as part of a congressional delegation to South Korea.

Mr. Wolff’s offices in Long Island and Washington were burglarized three times during the investigation, fueling speculation of misconduct, and his executive secretary was accused of perjury by the House Ethics Committee after she testified that Park’s contact information had never been in Mr. Wolff’s telephone file and that she had never removed or destroyed the information.

The congressman insisted that while he knew Park, he had never received improper donations — nor had he done so on previous trips to Korea. While other congressmen were offered suits, vases and gambling money, Mr. Wolff told the New York Times in 1977, he had received nothing more than flowers, “so many that our room looked like a funeral parlor.

“What they didn’t know,” he continued, “was that I am allergic to flowers and sneezed all over the place.”

Lester Lionel Wolff was born in Manhattan on Jan. 4, 1919. His father worked in marketing, a career that Mr. Wolff adopted after a brief foray into performance.

Young Lester appeared on children’s radio shows and received a scholarship to the Juilliard School, where he studied singing and tap-dance before transferring to New York University. Mr. Wolff later taught marketing at the school.

Because his asthma prevented him from serving in the military, he volunteered for the newly created Civil Air Patrol during World War II. Mr. Wolff served as a submarine chaser, helping to protect U.S. ships from German U-boats, and later organized and commanded a congressional wing of the Civil Air Patrol, which serves as the civilian auxiliary of the Air Force.

In 2014, Mr. Wolff accepted the Congressional Gold Medal, one of the nation’s highest civilian honors, on behalf of Civil Air Patrol members who served during the war.

Mr. Wolff entered politics after contemplating retirement in the 1960s, having served on U.S. trade missions to the Philippines, Malaysia and Hong Kong and interviewed politicians and other public figures as host of a New York-area television series, “Between the Lines.” One guest, then-Sen. John F. Kennedy, finished his interview with Mr. Wolff and quietly suggested that the host run for Congress.

Mr. Wolff’s political career ended in 1980, when he was defeated in his reelection bid by 27-year-old Republican candidate John LeBoutillier, who ran ads decrying Mr. Wolff’s “48 junkets to 42 different countries.” (LeBoutillier later called Speaker Thomas P. “Tip” O’Neill Jr. “fat, bloated and out of control — just like the federal budget” and lasted just one term in office.)

The campaign attack struck at Mr. Wolff’s close ties to East Asian countries and businesses, which served him well after he left Congress.

In the mid-1990s, he replaced Edward von Kloberg III, a flamboyant lobbyist to tyrants and despots, as a trade and public relations consultant to the government of Myanmar, also known as Burma. Mr. Wolff lobbied to restore U.S. funding and anti-narcotics cooperation to the country, aid that had been suspended ever since the Myanmar military opened fire on crowds of protesters in 1988. The death toll reached into the thousands, and the military established martial law under a group called the State Law and Order Restoration Council.

The SLORC, as it was known, became a deep-pocketed patron for Mr. Wolff, paying him $10,000 a month plus expenses — a salary that John Badgley, a Myanmar scholar at Cornell University, once described as “dope money.”

Mr. Wolff’s work in Myanmar extended through his leadership at a pair of New York-based groups, the Honest Ballot Association and Pacific Community Institute at Touro College, which organized congressional junkets to Myanmar that were paid for by that country’s government, according to New York magazine.

On some trips, according to The Washington Post, Myanmar officials introduced members of Congress to prominent heroin traffickers, under the pretense that the drug lords were leaders of ethnic minorities. Other “fact-finding” tours, wrote Bertil Lintner, a veteran journalist in Southeast Asia, “differed little from the well-orchestrated propaganda trips” of the 1930s Soviet Union, when intellectuals were shown the country’s highlights “while thousands of political prisoners languished in jail.”

Mr. Wolff succeeded at least partly in burnishing the junta’s reputation in Washington. After traveling on Wolff-sponsored tours, the Associated Press reported in 1994, U.S. Reps. Bill Archer (R-Tex.), Nancy Johnson (R-Conn.) and Mike Oxley (R-Ohio) all spoke positively about the country’s military regime.

Mr. Wolff’s wife of 56 years, the former Blanche Silver, died in 1997. In addition to his son, of Bethesda, Md., survivors include a daughter, Diane Yorg of Queens; four grandchildren; and four great-grandchildren.

With Mr. Wolff’s death, the oldest living former member of Congress is now Neal Edward Smith, 101, an 18-term Iowa Democrat who was first elected to the House in 1958.