Efforts by Southwest Airlines Co. to begin flights to Hawaii have fallen victim to the government shutdown.

The carrier has done all it can to secure certification to begin service but can’t move forward without approval from the Federal Aviation Administration for extended flights over water, or ETOPS, the Dallas-based airline said Monday in a statement. Southwest set no new timeline for selling tickets or beginning Hawaii flights.

“The groups within the FAA that oversee ETOPS authorizations are furloughed, and our next steps require their direct participation and oversight,” the carrier said.

Southwest had expected to begin selling tickets for Hawaii flights in late 2018 and to start service this quarter.