The airline has been in the crosshairs in a trade conflict in which U.S. aerospace giant Boeing accused Canadian rival Bombardier of selling its new C Series planes to Delta below the cost of production.
The U.S. Commerce Department sided with Boeing and recommended a duty of 300 percent on the some 100-seat C Series planes.
Airbus late Monday announced it agreed to take a majority stake in the imperiled Bombardier jet program.
Delta told investors on an earnings call last week that it "would not pay those tariffs" and after the Airbus deal said it still "looked forward" to taking delivery of the C Series jets. It declined to comment further on the deal Tuesday.
Delta, which has also been an important Boeing customer over the years, argued that Boeing no longer produces a similar product to the Bombardier jets.
The backing by Airbus, which produces the world's biggest passenger jet, the Airbus A380, even more closely pits the European plane-maker against Boeing.
Delta is unveiling its new Airbus A350, a widebody plane it intends to fly from the U.S. to Asia, on Tuesday. The twin-aisle plane is coming into service as Delta phases out its last Boeing 747s, the four-engine plane that some airlines have ditched in favor of more fuel-efficient twin-engine planes.