U.S. Customs and Border Protection is testing facial comparison technology at Hartsfield-Jackson International Airport to verify travelers' identities.

The test will involve passengers departing on Delta Air Lines' daily Atlanta-Tokyo flight from June 13 through Sept. 30, according to Customs.

Travelers will have their digital photo taken while showing their boarding pass before heading down the jet way for their flight. Travelers 15-78 years old will be required to go through the process, which is expected to take less than three seconds.

The agency said several Congressional mandates direct the Department of Homeland Security to record the arrival and departure of non-U.S. citizens by collecting biometrics. It plans to start doing so for those leaving the United States from the busiest airports in 2018.

CBP said images of travelers will be held in secure data systems for "post-departure analysis," and the data of travelers with U.S. passports will be deleted immediately once their identity is confirmed. For other travelers, the test data will be deleted after the test ends.

An airplane arrives at Hartsfield-Jackson Atlanta International Airport at sunrise, Thursday, March 24, 2016, in Atlanta. Following the Belgium bombings, U.S. cities and airports have raised security alerts. BRANDEN CAMP/SPECIAL

Credit: Kelly Yamanouchi

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Credit: Kelly Yamanouchi

"CBP remains committed to protecting the privacy of all travelers," according to U.S. Customs and Border Protection.

The agency already takes photos of travelers arriving back in the United States, and last year tested the use of facial comparison technology for some returning travelers at Washington Dulles airport.