Omar Saddiqui Mateen, the gunman that shot and killed nearly 50 people at a gay nightclub in Orlando Sunday, injuring dozens more, was an American-born citizen raised in the US operating with legally obtained weapons and "inspired by an extremist terrorist organization," President Barack Obama said at a White House briefing Monday.

"This is an example of the kind of homegrown extremism that all of us have been so concerned about for a very long time," Obama told reporters. At this time there is no evidence Mateen was directed by a larger organization or part of some larger plot, Obama said.

Now Obama is worried the debate will become an "either/or" conversation between gun control and tackling extremism.

"It's not an either/or; it is a both/and," he said to reporters after his briefing with FBI Chief James Comey.

The Orlando shooting is still in its preliminary investigation, Obama said, noting that it is being addressed as a "terrorist investigation" while also factoring in this attack's target on the LGBTQ community, as well as its implications on gun policies.

"We are also going to make sure we think about the risks we are willing to take by being so lax in how we make very powerful firearms available to people in this country," Obama said.

"My concern is that we start getting into a debate that is an 'either/or' debate. … It's not an either/or; it is a both/and. We have to go after these terrorist organizations and hit them hard, we have to counter extremism, but we also have to not make it easy for somebody who decides they want to harm the people in this country to be able to obtain weapons to get at them."

Homegrown terrorists have left a large imprint on the global psyche in the past year: In the most recent attacks in Paris and Brussels, as well as in San Bernardino, California, many of the attackers were born and raised in the countries they chose to strike.

As countries around the world target terror groups like al-Qaeda and ISIS on the ground, hitting their key personnel and foiling their plots, addressing extremism at home will be an issue American leadership will have to learn to "grapple with," Obama said at the briefing: