NEW YORK — The phone calls went out from Saigon’s ­Xa-Loi Buddhist pagoda to chosen members of the foreign news corps. The message: Be at a certain location tomorrow for a ‘‘very important’’ happening.

The next morning, June 11, 1963, an elderly monk named Thich Quang Duc, clad in a brown robe and sandals, assumed the lotus position on a cushion in a blocked-off street intersection. Aides drenched him with aviation fuel, and the monk calmly lit a match and set himself ablaze.

Of the foreign journalists who had been alerted to the shocking protest against South Vietnam’s United States-supported government, only one, Malcolm Browne of the Associated Press, showed up.

The photos he took appeared on front pages around the globe and sent shudders all the way to the White House, prompting President John F. Kennedy to order a reevaluation of his administration’s Vietnam policy.

‘‘We have to do something about that regime,’’ Kennedy told Henry Cabot Lodge, who was about to become US ambassador to Saigon.

Mr. Browne, who died Monday at a New Hampshire hospital at age 81, recalled in a 1998 interview that that was the beginning of the rebellion, which led to South Vietnamese President Ngo Dinh ­Diem being overthrown and murdered.

‘‘Almost immediately, huge demonstrations began to develop that were no longer limited to just the Buddhist clergy, but began to attract huge numbers of ordinary Saigon residents,’’ Mr. Browne said.

Mr. Browne was diagnosed with Parkinson’s disease in 2000 . He was rushed to the hospital Monday after experiencing difficulty breathing, said his wife, Le Lieu Browne, who lives in Thetford, Vt.

Mr. Browne spent most of his journalism career at The New York Times, where he put in 30 years of his four decades as a journalist, much of it in war zones.

By his own account, Mr. Browne survived being shot down three times in combat aircraft, was expelled from half a dozen countries and was put on a ‘‘death list’’ in Saigon.

In 1964, Mr. Browne, then an AP correspondent, and rival Times journalist David Halberstam both won Pulitzer Prizes for their reporting on the conflict in Vietnam. The war had escalated because of the Nov. 1, 1963, coup d’etat in which ­Diem was killed.

The plot — by a cabal of generals acting with tacit US approval — was triggered in part by earlier Buddhist protests against the pro-Catholic Diem regime. These drew worldwide attention when the monk set himself afire in protest as about 500 people watched.

One of his monk photos became one of the first iconic photos of the Vietnam War.

Former AP reporter Peter Arnett, who also won a Pulitzer Prize for his work in Vietnam, said in an e-mail: ‘‘Malcolm Browne’s personal bravery, his intellectual brilliance and uncompromising dedication to the truth set the high standard of AP reporting from Vietnam in the critical early years of the war. He gave unselfish encouragement to the many young journalists arriving to cover their first war. His example was inspirational to me in the four years I worked with him in the Saigon bureau, and I valued him as a mentor for the rest of my career.’’

Hal Buell, who was a deputy photo editor in New York City when the photo of the monk was taken, said, ‘‘That picture put the Vietnam War on the front page more than anything else that happened before that.’’

Malcolm Wilde Browne was born in New York on April 17, 1931. He graduated from Swarthmore College in Pennsylvania with a degree in chemistry. Working in a lab when drafted in 1956, he was sent to Korea as a tank driver, but by chance got a job with a military newspaper, and from that came a decision to trade science for a career in journalism.

He worked first for the Middletown Daily Record in New York, where he worked alongside Hunter S. Thompson. Mr. Browne then worked briefly for International News Service and United Press before joining the AP in 1960. A year later, the AP sent him to Saigon to head its expanding bureau.

There, he became a charter member of a small group of reporters covering South Vietnam’s US-backed military struggle against the Viet Cong, a home-grown communist insurgency.

Within the year he was joined in Saigon by photographer Horst Faas and by Arnett.

In his 1993 memoir, ‘‘Muddy Boots and Red Socks,’’ Mr. Browne said he ‘‘did not go to Vietnam harboring any opposition to America’s role in the Vietnamese civil war’’ but became disillusioned by the Kennedy administration’s secretive ‘‘shadow war’’ concealing the extent of US involvement.

By 1965, impressed by how television appeared to be dominating the public discourse, the reporter who had never owned a TV set left the AP to join ABC News in Vietnam.

Mr. Browne quit ABC after a year over management questions. He joined The New York Times in 1968.