He warned specifically that persecuted Rohingya Muslims there could become radicalized and destabilize the region unless the government contained sectarian violence and discrimination.
The government of Myanmar has waged a brutal campaign against Rohingya immigrants from neighboring Bangladesh. The United States has denounced it as ethnic cleansing.
“Surin was the most intellectually vibrant yet humane leader Southeast Asia has produced in the past 30 years,” Amitav Acharya, a professor of international relations at American University in Washington, said in an email.
“He possessed an unusual combination of intellectual sophistication, gracefulness, personal humility and an ease of communicating with diverse audiences,” Professor Acharya added.
In Thailand, where military dictatorships have dominated under a constitutional monarchy, Mr. Surin lobbied to restore democracy.
As the secretary general of the Association of Southeast Asian Nations, he fostered a concerted agenda among member nations that are flanked by two regional giants, China and India, and are home to more than 640 million people divided by language, religion, historical rivalries and the geography of sprawling archipelagos.
He sought to minimize territorial disputes and to encourage members of the association to share natural resources in the South China Sea.
“Surin presented a credible, assured face to the world in a region that more often confuses and confounds its international partners,” Michael Vatikiotis, an author and Asia director of the Center for Humanitarian Dialogue, a private group that fosters diplomacy over armed violence, wrote this week in The Nikkei Asian Review.
Surin Abdul Halim Bin Ismail Pitsuwan was born on Oct. 28, 1949, in the southern province of Nakhon Si Thammarat, the son of Islamic educators.
Educated largely through grants from the Rockefeller Foundation and the Winston S. Churchill Association, he received a bachelor’s degree in political science from Claremont Men’s College (now Claremont McKenna College) in California in 1972 and a master’s and doctorate in political science and Middle Eastern studies from Harvard.
He returned to Thailand and was teaching at Thammasat when he received a Congressional Fellowship from the Asia Foundation. He was hired by Representative Geraldine A. Ferraro of Queens a year before Democrats nominated her for vice president, in 1984. He had submitted his résumé to Ms. Ferraro writing, “I am available for six months of free labor, but first-class service, in foreign affairs, human rights and Asian affairs.”
He went on to write news releases and statements for the congresswoman commemorating national holidays celebrated by Queens’s many ethnic groups.
After returning to Thailand, Mr. Surin was elected to the Thai House of Representatives in 1986. He served as foreign minister from 1997 to 2001.
Survivors include his wife, Alisa Pitsuwan, and three children.