According to law enforcement sources ... the FBI had a meeting with city and state officials Tuesday to lock down the final details of the overall security plan for SB 53 -- which will be held February 3 at Mercedes-Benz Stadium.

We're told the Atlanta PD is the lead law enforcement agency responsible for safety at the event, but -- like at prior Super Bowls -- it will team up with FBI agents and the Department of Homeland Security to make it happen.

FBI Specialist Kevin Rowson tells us the agency's role is twofold -- it coordinates the collection and dissemination of all operational intelligence ... but it also steps up to take over in the case of an act of terrorism or if any crime rises to a federal level.

In the past, the FBI's role in security has included conducting the background checks for ALL of the event day staff who will be credentialed ... including security guards, food vendors, media and volunteers. That can mean as many as 30,000 individuals.

Rowson says ... "Our plans for the Super Bowl security have not changed despite the shutdown."

DHS Press Secretary Tyler Q. Houlton adds, "The Department takes the security of high risk events like the Super Bowl extremely seriously ... the current lapse in government funding will have no effect on our commitment to assuring a safe and secure event."

ATL PD's Public Affairs Director agrees, telling us ... "We’re confident our federal law enforcement partners will continue to assist us every step of the way and anticipate no impact from the shutdown."

As you'll recall ... security for last year's SB in Minneapolis resembled a militarized zone, with armed police officers and Humvees on the scene.