Information provided by the CIA helped to prevent a series of terrorist bombings in St Petersburg, Russia.
Vladimir Putin phoned Donald Trump to thank him for the tip-off, the Kremlin said.
The information allowed Russian security services track down and detain a group of suspects who were planning bomb attack on the Kazansky Cathedral and other sites in Russia's second-biggest city.
The Kremlin said the Russian President asked his US counterpart to convey his gratitude to the CIA.
