Delta Air Lines Inc. will restart two weekly flights between the U.S. and China next week, bringing its total to four, because of increased customer demand and recent government approval for such service.

The flights will depart from Seattle and Detroit starting Aug. 24 and fly to Incheon International Airport in Seoul before continuing to Shanghai Pudong International Airport, the carrier said in a statement Wednesday. Delta resumed twice-weekly flights on the Seattle route in late June after suspending all China service in February amid the coronavirus outbreak.

The U.S. will allow Chinese airlines to fly eight round trips between the two countries, with flying limited to four Chinese carriers currently approved for passenger flights, the U.S. Transportation Department said Tuesday. The action followed the Chinese government’s decision to allow Delta and United Airlines Holdings Inc. to double their China service to four weekly flights each.

United also will double to four its weekly flights between San Francisco and Shanghai Pudong, with the same stop at Incheon, the carrier said Tuesday. The flights start Sept. 4 but can be booked online beginning Aug. 19.