President Obama today said that Sen. Lindsey Graham, R-S.C., is "wrong" that there was not adequate intelligence shared in the days and months leading up to the Boston Marathon bombings.

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

In the two weeks since the bombings in Boston, Graham has criticized the Obama administration, asking why more was not known about the foreign-born Tsarnaev brothers who are suspected in the bombings or shared among agencies.

"This administration is letting its guard down, and it is beginning to show," Graham said on Fox News last week.

He echoed the sentiment in the hallways of Capitol Hill last Thursday after an all-senators briefing on national security issues by Secretary of State John Kerry, where Boston, among other topics, was discussed.

"Boston is becoming to me a case study is system failure," Graham said. "Between Benghazi and Boston, our systems are failing and we are going backwards. We need to understand that bin Laden may be dead but the war against radical Islam is very much alive. Radical Islam is on the march and we need to up our game."

Today, at a presidential press conference in the Brady briefing room, President Obama was asked by a reporter about claims by Graham and other senators that in the years after the 9/11 terrorists attacks the nation has gone backward on national security.

"No, Mr. Graham is not right on this issue, although I'm sure [he] generated some headlines," the president answered curtly.

Graham issued a news release minutes after the president left the podium at the White House.

"With all due respect Mr. President, Benghazi and Boston are compelling examples of how our national security systems have deteriorated on your watch," Graham said. "If Benghazi is not an example of system failure before, during and after the attack what would be? If Boston is not an example of a pre-9/11 stovepiping mentality what would be?"

Though they're sparring publicly, Obama and Graham also depend upon each other for passing the big ticket items that are in each of their interests legislatively, such as immigration reform and battles over the debt.

Graham is one of the Republican members of the bipartisan Gang of Eight that recently proposed a sweeping immigration reform bill in Congress. The group will rely heavily on President Obama's endorsement, support and public push for the bill in the weeks and months ahead.

President Obama, 100 days into his second term, has set immigration reform as one of his top second-term priorities, a goal that will only be reached with Congress' help.

Today, he said that although there is "dysfunction" on Capitol Hill, he still has the juice to get his agenda though a divided Congress, though Graham sometimes leads the charge against him.

READ: Obama: I've Still Got Juice

"As Mark Twain said, rumors of my demise may be a little exaggerated at this point," the president said today.