Putin called President Trump thanking him for the work of the CIA in helping thwart a terrorist attack in St. Petersburg.

Read: Special Counsel Robert Mueller Now Has ‘Tens of Thousands’ of Trump Transition Emails

According to a statement by the Kremlin, Putin reportedly expressed gratitude for the intelligence provided by the CIA, which allowed for the search and detention of individuals planning the attack. They were reportedly targeting the Kazan Cathedral, an Orthodox Christian church in the heart of the city, as well as other crowded sites.

The attack had been planned for Sunday, which The New York Times noted was just two days after the first arrests were made. It was reportedly on orders of the Islamic State, and the search of one apartment revealed explosives, automatic weapons, and extremist literature.

Read: President Trump: U.S. Economy to ‘Rock’ as GOP Races to Tax Vote

Putin asked Trump to convey his message of thanks to the CIA, and also assured Trump that Russian law enforcement agencies would similarly hand over any information about potential terror threats in the U.S. to their counterparts.

The public cooperation of American and Russian intelligence agencies is significant, not least because the CIA had previously identified Russia’s Federal Security Service as one of the agencies involved in the 2016 hacking of the Democratic National Committee computers.

An official White House readout said that Trump “appreciated the call” and was “pleased to have helped save so many lives.” He also reiterated the importance of “intelligence cooperation to defeat terrorists,” and both leaders reportedly “agreed that this serves as an example of the positive things that can occur when our countries work together.”