The Trump administration has ordered Delta Air Lines to terminate its joint venture partnership with Aeromexico by Jan. 1.

The antitrust immunity deal has been in place for almost nine years and allowed the airlines to coordinate on schedule, pricing and capacity for flights between the United States and Mexico.

According to the Department of Transportation's Sept. 15 order, the decision to force the end of the partnership is based on "ongoing anticompetitive effects in U.S.-Mexico City markets that provide an unfair advantage to Delta and Aeromexico."

Transportation Secretary Sean Duffy said in a statement the decision came in response to the Mexican government's decision to move all-cargo airlines out of Mexico City's main airport in 2022.

Delta said in a statement it is "disappointed" by the DOT's decision, which it said will "cause significant harm to U.S. jobs, communities and consumers traveling between the U.S. and Mexico."

Delta Air Lines was not immediately able to provide details to USA TODAY about how the wind down would occur and said it is reviewing the order and evaluating options.

It's unclear what effect, if any, the termination of the partnership will have on passengers.

"All flights will continue to operate as normal, unless otherwise contacted by Delta," Delta's statement said.

The DOT said in a statement that the airlines will be able to continue working together cooperatively in other ways.

"Delta and Aeromexico will be able to continue their partnership through arms-length activities such as codesharing, marketing, and frequent flyer cooperation," Delta's statement said. "Delta will also be able to retain its equity stake in Aeromexico and both carriers can maintain all of its existing flying in the U.S.-Mexico market unimpeded."

Zach Wichter is a travel reporter and writes the Cruising Altitude column for USA TODAY. He is based in New York and you can reach him at zwichter@usatoday.com.

This article originally appeared on USA TODAY: Delta forced to end Aeromexico deal. What it means for travelers.

Reporting by Zach Wichter, USA TODAY / USA TODAY

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