Dhaka, Dec. 6 -- China Eastern Airlines has launched what it says is the world's longest direct scheduled passenger flight, linking Shanghai and Buenos Aires via Auckland, the carrier said .

The inaugural service departed Shanghai Pudong International Airport on Dec. 4 and arrived in the Argentine capital after about 25 hours in the air, covering roughly 20,000 km.

The flight includes a two-hour stop in Auckland, New Zealand, during which passengers stay on the same aircraft under the same flight number.

Because of the layover, the service is classed as direct rather than non-stop.

The southern routing shortens travel times compared with traditional northern options through Europe or North America, which usually involve multiple conne...