Presidents Vladimir Putin and Barack Obama agreed on Monday to maintain close contacts between U.S. and Russian intelligence agencies and cooperate to ensure security for the 2014 Olympics that Russia is hosting in Sochi, the Kremlin said.
Putin and Obama spoke for at least the second time since the April 15 Boston Marathon bombings, which U.S. authorities believe were carried out by two brothers with roots in Russia's volatile and mostly Muslim North Caucasus.
In a call initiated by the United States, they discussed "the issue of stepping up interaction between the special services in the context of the recent terrorist act in Boston," a Kremlin statement said.
"The presidents reached a practical agreement about active contacts between the special services and their leaders," it said, adding that both also "underscored the importance of joint work providing security for the security of the Sochi Olympics".
Special services is a term Russians use for security and intelligence agencies.
The reputation of Putin, a former KGB spy, is riding on ensuring the Games pass off peacefully in Sochi, which is near the volatile North Caucasus.
Putin has in the past accused Washington of double standards in its approach to militants, depending on its geopolitical goals, and of underestimating the threat posed by Islamist extremists in the North Caucasus.
He told national television last week that the Boston bombings justified his tough line on the North Caucasus and showed that Russia and the United States must step up cooperation on security.
After a previous call around the time suspect Dzhokhar Tsarnaev was captured after his brother Tamerlan was shot dead by police, the Kremlin said Obama and Putin agreed the nations should step up counter-terrorism cooperation.
The White House said at the time that Obama had thanked Putin for Russia's close cooperation on counter-terrorism.
U.S. officials have said Russia separately tipped off the FBI and the CIA in 2011 with concerns that Tamerlan Tsarnaev may have been a radical Islamist, raising questions about U.S. authorities' handling of the case.
Russian-U.S. relations have been badly strained by what Putin's critics call a clampdown on dissent since he returned to the Kremlin last May, but both sides have signalled they want to improve ties and cooperate on security despite disagreements.