ATLANTA (Reuters) - Delta Air Lines (>> Delta Air Lines, Inc.) said on Tuesday it was unclear when the Bombardier CSeries (>> Bombardier, Inc.) jets would be delivered, as a proposed U.S. government tariff on the planes complicates the future of the Canadian-made aircraft.

Speaking to reporters in Atlanta, Chief Operating Officer Gil West said the delivery schedule of the plane was still "something of a question mark."

On Monday, Airbus SE (>> Airbus SE) agreed to take a majority stake in CSeries jetliner programme, a deal that could allow the Canadian planemaker to sidestep U.S. tariffs threatened in a trade dispute with Boeing (>> Boeing Company (The)).

(Reporting by Alana Wise; Editing by Nick Zieminski)