Southwest Airlines said it has received FAA approval to begin its long-awaited Hawaii flights.

The airline said it will announce details on ticket sales and inaugural flights in the "coming days.''

Southwest CEO Gary Kelly previously said Southwest would start selling tickets within days of receiving FAA certification for long overwater flights, a process called ETOPS, or extended range twin engine operational performance standards.

Kelly has said the first flights would begin within weeks of receiving approval. The airline's efforts to gain FAA approval were delayed by the government shutdown, so it's possible Southwest will start flights soon after the ticket sales begin to make up for lost time.

Southwest formally announced plans to begin Hawaii service in October 2017. It has dribbled out details since. Last year, the airline said it planned to serve four islands in Hawaii: Oahu, which is home to Honolulu; Maui, Kauai and the Big Island of Hawaii, home to Kona.

It will fly from four California cities: San Diego, Sacramento, San Jose and Oakland.