Delta Air Lines has added 30 incremental A321neo aircraft to its existing order book with Airbus. The A321neo is Delta’s most fuel-efficient large-gauge narrowbody aircraft.

“Adding these aircraft strengthens Delta’s commitment to replacing older fleets with more sustainable, fuel-efficient jets, and offers the best customer experience in the industry,” Mahendra Nair, Delta’s senior vice president of fleet and techops supply chain said in a statement.

“Delta appreciates the extensive partnership with the Airbus team in support of our strategic growth plans, and we look forward to continuing to work together throughout the recovery and in the years ahead.”