The bombing "should push us closer in fending off common threats, including terrorism, which is one of the biggest and most dangerous of them," Putin said according to The Associated Press.

"The cause isn't in their ethnicity or religion, it's in their extremist sentiments," Putin said.

After a four-day manhunt following the Boston Marathon bombing that resulted in three dead and hundreds injured, authorities arrested Dzhokhar Tsarnev, one of the two brothers said to have caused the bombing. Dzhokhar, and his brother, Tamerlan, are Chechen by origin. Tamerlan died in a shootout with police during the manhunt.

At the request of the Russian government, the FBI investigated Tamerlan and concluded in 2011 that he was not a threat. Since the bombing a number of lawmakers have suggested that the FBI should review its procedures for how it handles tips and investigations.

On Wednesday, Rep. Peter King (R-N.Y.), the former chairman of the House Homeland Security Committee, said that the FBI should be given more flexibility for how it handles possible threats.

"The FBI should be given much more flexibility since we have these ongoing threats, and it's very seldom that we're going to get a specific piece of information that's going to tie someone to a threat," King said. "It's always going to be bits and pieces, so it may very well be that the FBI has to review what its procedures and regulations are here."