Washington CNN — 

After nearly two decades, passengers going through airport security in the United States will no longer have to take their shoes off.

The Transportation Security Administration will be phasing out the security requirement, a government source familiar with the matter confirmed to CNN on the condition of anonymity.

The White House Press Secretary responded to the reports on X, calling it “big news” from the Department of Homeland Security.

An internal memo announcing the change, which was first reported by the blog Gate Access, was not officially confirmed by the TSA.

“TSA and DHS are always exploring new and innovative ways to enhance the passenger experience and our strong security posture,” TSA public affairs said in a statement. “Any potential updates to our security process will be issued through official channels.”

Passengers flying out of Hancock International Airport in Syracuse, New York, did not have to take off their shoes on Monday, CNN affiliate WSTM reported. However, on Tuesday morning at Chicago O’Hare, CNN affiliate WLS saw passengers still being asked to remove footwear.

In December 2001, Richard Reid, who became known as the “shoe bomber,” tried to use matches to ignite explosives hidden in his shoes on a flight from Paris to Miami.

The requirement for passengers to take their shoes off at TSA security checkpoints came nearly five years later due to “intelligence pointing to a continuing threat,” an official TSA history notes, following a foiled August 2006 terrorist plot to detonate liquid explosives onboard transatlantic flights. The TSA introduced its 3-1-1 liquids rule for carry-on luggage in response.

Participants in the Trusted Traveler Program TSA PreCheck have long been able to avoid removing shoes, however they must submit to a background check and pay an application fee.

CNN’s Kara Devlin contributed to this report.