MOSCOW — Members of a congressional delegation visiting Moscow to investigate the background of the Boston Marathon bombing suspects said Sunday that the attack might have been prevented by greater cooperation between the United States and Russia on intelligence issues and counterterrorism efforts.
But the lawmakers said they could not point to any specific misstep by the United States or Russian intelligence services, and they did not offer any new insights into what motivated the suspects, two brothers with family ties in Russia’s North Caucasus, to commit the attack.
“Yes, it could have been averted [if] both countries were working together on a much higher level,” said Representative Dana Rohrabacher, a California Republican who led the delegation and is the chairman of the House Foreign Affairs Subcommittee on Europe, Eurasia, and Emerging Threats.
The six-member delegation, which included Representative William Keating of Massachusetts, received a rare, high-level briefing at the headquarters of the Russian Federal Security Service, called the FSB.
They were told about the agency’s efforts to warn the US officials about the older suspect, Tamerlan Tsarnaev, and his mother, Zubeidat Tsarnaeva, and the likelihood that they harbored extremist views.
Tamerlan Tsarnaev, who is accused of carrying out the Boston bombings with his younger brother, Dzhokhar, was killed during a police pursuit. His brother was wounded and is in custody.
Keating, who returned home before the delegation’s news briefing at the US Embassy in Moscow, said later Sunday that the Russian director of counterintelligence told the group the two countries were not sharing counterterrorist information in 2010 and 2012 on the same level as they are now.
“Had they been exchanging information the way they are currently doing . . . this may have been averted,’’ Keating said, expanding on comments he made to the Globe last week.
“There would have been situations where the two countries would have had [Tamerlan Tsarnaev] under surveillance and scrutiny and that would have made a potential difference,’’ the Bourne Democrat said.
“It’s only hypothetical now, sadly,’’ Keating said. “And we use that information as a springboard for better communication and shared intelligence going forward.”
Tamerlan Tsarnaev spent six months in the southern republic of Dagestan last year, and investigators have been trying to determine whether he had contacts with the militants there.
The members of the delegation praised the cooperation they received from Russian authorities but said that they had been unable to get details about the circumstances of Tsarnaev’s return to the United States after the visit to Dagestan in the Caucasus.
They said Russian officials confirmed reports that Tsarnaev left Dagestan two days after an acquaintance, who was a member of a Muslim rebel group, was killed during a security operation. But the lawmakers said that the Russian authorities could not tell them when Tsarnaev had purchased his airline ticket or whether he had left in a rush, fearing for his life.
“You wonder, was that a cause and effect, but nobody here seems to have thought about that,” said Representative Steve Cohen, a Tennessee Democrat who was part of the delegation.
Rohrabacher, speaking at the news conference, said he had no reason to conclude that the FBI or the Obama administration had mishandled the warnings from Russia. Rather, he said, the relationship with Russia in general should have been stronger.
“I can’t blame them for not doing right within the context of the status quo, but these are people who are supposed to be changing and trying to reform the status quo,” he said of the administration. “And I would blame them for that.’’
“I would say both the Obama administration as well as the Republican administration before Obama, that we have allowed attitudes, maybe the attitudes from the Cold War, to remain in place, that have prevented a level of cooperation that is justified,” Rohrabacher said.
In his criticism of both Republicans and Democrats, and his calls for much closer collaboration with the Russians, potentially including joint military exercises, Rohrabacher strayed far from his own party’s traditional distrust of the Kremlin. And he said that President Vladimir V. Putin had been unfairly maligned in the United States.
“Everything that the Russians do that can be described in sinister words and anything that Mr. Putin does that can be described in sinister words are described in sinister words in the United States,” he said.
Adding an odd celebrity touch, the action-film star Steven Seagal, who has a following in Russia, joined the lawmakers. Seagal helped arrange meetings and even offered to take the lawmakers to Chechnya to meet Ramzan Kadyrov, the region’s leader, who has been accused of human rights abuses.
The Chechnya visit was called off for logistical reasons, but Rohrabacher thanked Seagal and said he was instrumental in securing some meetings, including a session with Dmitry Rogozin, a deputy prime minister.
“I don’t know that he would have been available to us if not for Steven’s role,” Rohrabacher said.
Representative Steve King, an Iowa Republican, said that the United States and Russia could be formidable partners in fighting terrorism.
“If Americans and Russia can conquer space together, we can defeat radical Islam together, and that’s why I came here, to advance that,” he said.
Also on the congressional trip were Michele Bachmann, a Minnesota Republican, and Paul Cook, a California Republican, who also left before the embassy news conference.
Seagal, who attended the Moscow news conference, is well connected in Russia. He met with Putin in March and visited Kadyrov last week in Chechnya, a province in southern Russia that has seen two wars between federal troops and separatists since 1994.
Those wars spawned an Islamist insurgency that spread across the Caucasus region .