John Brennan, the director of the Central Intelligence Agency (CIA), made a secret visit to Moscow in March, according to Russian Deputy Foreign Minister Oleg Syromolotov. The visit, he said, had nothing to do with Russia's decision two weeks ago to begin withdrawing from Syria.

“It’s no secret that Brennan was here,” Syromolotov was quoted by the Interfax news agency as saying Monday. “But he didn't visit the Foreign Ministry. I know for sure that he met with the Federal Security Service (the successor agency to the Soviet KGB), and someone else.”

It wasn't clear why Brennan visited Moscow, but the trip appears to have coincided with President Vladimir Putin's surprise March 14 announcement that Russia's combat operation in Syria was ending, and Moscow would soon withdraw a portion of its forces from the country after conducting 167 air strikes.

The decision to withdraw was followed by a visit of U.S. Secretary of State John Kerry to Moscow last week. While in Russia, Kerry met personally with Putin and his foreign minister, Sergei Lavrov.