WASHINGTON – President Obama offered his support Tuesday for the FBI's handling of a Russian intelligence tip about a suspect in the Boston Marathon bombings, even as the nation's intelligence chief ordered a review of whether more could have been done to thwart the attack.

Obama rejected criticism that the FBI did not do enough when the Russian government asked it to investigate Tamerlan Tsarnaev in 2011. The FBI interviewed Tsarnaev at the time but found no evidence that he was involved in radical activities that represented a threat to the United States.

"It's not as if the FBI did nothing," Obama said at his first news conference since Tsarnaev and his brother, Dzhokhar Tsarnaev, were accused of setting off bombs at the marathon on April 15. "They not only investigated the older brother, they interviewed the older brother. They concluded that there were no signs that he was engaging in extremist activity."

"Based on what I've seen so far," he added, "the FBI performed its duties. Department of Homeland Security did what it was supposed to be doing. But this is hard stuff."

James R. Clapper Jr., who as the director of national intelligence oversees the country's 17 intelligence agencies, said a review would look at how the FBI and CIA handled the Russian tip and its aftermath. Obama and law enforcement officials described the action as standard procedure.

Clapper's office said the review was initiated by the Office of Intelligence Community inspector general and would be coordinated with the inspectors general from the Justice Department and the CIA.

"Director Clapper believes that every agency involved in collecting and sharing information prior to the attack took all the appropriate steps," his office said in a statement. "He also believes that it is prudent and appropriate for there to be an independent review of those steps to ensure that nothing was missed."

The FBI's handling of the Boston case has come under fire from some in Congress. Sen. Lindsey Graham, R-S.C., has said that "the ball was dropped" because the agency did not identify Tamerlan Tsarnaev as a threat after the original Russian tip or continue tracking him when he left to visit his family in Russia and later returned to the United States.

Obama responded Tuesday by implying that Graham was simply seeking attention. "Mr. Graham is not right on this issue, although I'm sure it generated some headlines," the president said.

Obama said that because of the pressure put on Al-Qaida and other networks, the danger to the United States seemed to be shifting more toward individuals who become radical on their own. He said, however, that the intelligence agencies were examining what happened in the case of the Tsarnaev brothers to see whether changes in policy would make a difference in the future.