A Delta passenger managed to take a gun through security in Atlanta and onto a flight to Tokyo on Jan. 2.

The Transportation Security Administration confirmed the incident of the in a statement to USA TODAY. Flight DL295 left Atlanta Hartsfield-Jackson International Airport for Japan's Narita International Airport.

"TSA has determined standard procedures were not followed and a passenger did, in fact, pass through a standard screening TSA checkpoint with a firearm at Hartsfield-Jackson Atlanta International Airport," according to the agency. "TSA will hold those responsible appropriately accountable."

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In its statement, TSA rejected the notion that the security breach was related to staff calling out from work amid the government shutdown.

"There was not a staffing issue as some are speculating or alluding to in their articles, it read. "In fact, the national callout percentages were exactly the same" on Jan. 2 and Jan. 3, "when there was no shutdown," the TSA added.

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A source at the airline told ABC News the gun owner filled airline workers in on what occurred upon arriving in Japan. Airline officials then informed the TSA .

"The passenger, who was fully cooperative with authorities, flew from Atlanta to Narita, Japan and was met by Japanese authorities upon landing," the agency continued.

In 2017, 4,000 firearms were reportedly taken at TSA checkpoints, The Washington Post notes.

USA TODAY has reached out to both airports for comment.