An American Airlines flight was forced to slam on the brakes during takeoff after a cargo plane crossed a runway at Los Angeles airport “without authorization,” according to authorities.

American Airlines Flight 2453 aborted its takeoff from Los Angeles International Airport to Boston after the crew noticed another aircraft on the runway Sunday morning, American Airlines said in a statement to The Post.

The cargo plane, Aerologic Flight 619, was crossing the runway “without authorization,” the Federal Aviation Administration said in a statement.

Air traffic controllers then immediately instructed the American flight, with 94 passengers and seven crew members aboard, to halt takeoff, according to authorities.

The plane was going roughly 154 miles per hour before it was instructed to slam on the brakes, according to data from Flightradar24.

At one point, the two aircraft were roughly 5,200 feet apart from each other, the FAA said.

The American flight later departed for Boston without a hitch, according to American Airlines.

“We thank our crew members for their quick action and our customers for their understanding,” the airline said in a statement.