MOSCOW — Yuri Drozdov, the Soviet spymaster who oversaw a sprawling network of KGB agents abroad, died Wednesday. He was 91.

The Foreign Intelligence Service, a KGB successor agency known under its Russian acronym SVR, didn’t give specifics in a terse statement.

Drozdov, a World War II veteran, joined the KGB in 1956 and was dispatched as a liaison officer with the East German secret police, the Stasi. In 1962, he took part in the exchange of Soviet undercover agent Rudolf Abel, convicted in the U.S., for downed American spy plane pilot Francis Gary Powers.

The story was made into Steven Spielberg’s blockbuster “Bridge of Spies” in 2015 as well as the Soviet movie “The Shield and the Sword,” a 1968 classic that Russian President Vladimir Putin once said inspired him to join the KGB.

Putin himself on Wednesday offered condolences to Drozdov’s wife and two sons in a message published on the Kremlin’s website. Drozdov was “a legendary spy and an outstanding professional” who was also “an incredible person and true patriot,” Putin said.

Working under diplomatic cover, Drozdov served as the KGB resident in China in 1964-68, and in the U.S in 1975-79.

In 1979, he came to head a KGB department overseeing a network of undercover agents abroad, the job he held until resigning in 1991. The agents who lived abroad under false identity were called “illegals” and were considered the elite of Soviet intelligence.

In December 1979, Drozdov led an operation to storm the palace of Afghan President Hafizullah Amin that paved the way for the Soviet invasion.

Drozdov also founded the KGB’s Vympel special forces unit intended for covert operations abroad.

The SVR praised Drozdov as a “real Russian officer, a warm-hearted person and a wise leader.”