MOSCOW (AP) - The head of a United States congressional delegation said on Sunday that its meetings in Russia showed there was "nothing specific" that could have helped prevent the Boston Marathon bombings, but that the two countries need to work more closely on joint security threats.

Representative Dana Rohrabacher, a California Republican who led the six-member delegation, described discussions with Russian Parliament members and security officials as productive. Some of the meetings, he said, were made possible by actor Steven Seagal.

Seagal, who attended the news conference at the US Embassy, is well-connected in Russia. He met Russian President Vladimir Putin in March, and last week paid a visit to Mr Ramzan Kadyrov, the strongman who rules Chechnya, a province in southern Russia that has seen two brutal wars between federal troops and Chechen separatists since 1994.

Those wars spawned an Islamic insurgency that spread across the region, including to neighboring Dagestan, now the centre of the violence. Tamerlan Tsarnaev, who was accused of carrying out the Boston bombings with his younger brother, spent six months in Dagestan last year. Investigators have been trying to determine whether he had contacts with the militants there.

Representative Steve King said Russian security officials told the delegation they believed that Tsarnaev and his mother had been radicalised before moving to the US in 2003. "I suspect he was raised to do what he did," said Representative King, a Republican from Iowa.

His account of the meeting at the FSB, the successor to the Soviet-era KGB, was disputed by Representative Steven Cohen, an Iowa Democrat, who said he understood that the radicalisation took place much later, when the family was living in Boston.

Representative Rohrabacher said a higher level of cooperation between the US and Russia is necessary to keep people safe in both countries. "Radical Islam is at our throat in the United States, and is at the throat of the Russian people," he added.

The congressman repeatedly thanked Seagal, who took credit for arranging the congressmen's meeting at the FSB, and said it helped avoid the experience of past foreign trips, when all of the meetings had been arranged by the US Embassy.

"You know what we got? We got the State Department controlling all the information that we heard," Representative Rohrabacher said. "You think that's good for democracy? No way!"