Seeger, who lived in Silver Spring, Md., died of pneumonia Monday in a hospital in Olney, Md., said his son, Stephen M. Seeger.
Seeger, who had studied communism and the Soviet Union as a Nieman Fellow in journalism at Harvard University in the early 1960s, was named chief of The Times' Moscow bureau in 1972.
While based in Moscow, he focused on the plight of Soviet Jews who wanted to go to Israel but were denied exit visas, and the problems of the so-called captive nations: the Baltic states of Estonia, Latvia and Lithuania.
"He addressed the subjects that interested him with great energy and produced some memorable copy," said Robert W. Gibson, a former Times foreign editor.
With two colleagues, he interviewed dissident author Alexander Solzhenitsyn a few hours before he was expelled from Russia in 1974.
In his 2005 book "Discovering Russia: 200 Years of American Journalism," Seeger described the intimidation and harassment that foreign correspondents experienced. At one point, a KGB colonel denounced Seeger as "the most disliked American correspondent since Harrison Salisbury" of the New York Times.
"You think this is an underdeveloped country," the colonel told Seeger.
While saying he was flattered to be compared to Salisbury, Seeger said he could not determine if Russia was "the most developed, undeveloped country or the least developed, developed country."
In 1975, Seeger joined the Bonn bureau and three years later opened a bureau in Brussels, where he served as European economics correspondent.
He left The Times in 1981 and was appointed director of information for the AFL-CIO. After a brief stint as public affairs director for Radio Free Europe-Radio Liberty, he moved to Singapore in 1987 to consult for the Straits Times.
Returning to Washington in 1990, he was assistant director of the External Relations Department of the International Monetary Fund and retired in 1994.
Born July 1, 1929, in Lackawanna, N.Y., Seeger grew up in nearby Hamburg, N.Y. He received a bachelor's degree in journalism and political science from the University of Iowa in 1951.
Seeger, who served in the U.S. Naval Reserve, was a reporter for the Buffalo Evening News and the Cleveland Plain Dealer before covering labor for the New York Times from 1964 to 1965.
Besides his son, he is survived by his wife, Palma; his sister, Elizabeth Morris; and two grandsons.