Southwest Airlines Co. has warned employees that it will announce some tough decisions in coming days under a plan to restore profits and help fend off changes being demanded by activist Elliott Investment Management.

Steps the carrier has already announced, including ditching a 50-year history of not assigning seats, offering a premium product and beginning red-eye cross-country flights, aren’t sufficient to improve its finances to the extent needed. That’s driving plans to eke out more revenue through changes to its route and flight network, Chief Operating Officer Andrew Watterson told employees in a video.

“There are some difficult decisions coming as well,” Watterson said in the video, a transcript of which was obtained by Bloomberg News on Saturday. “Not city closures. But you know, bigger changes for some cities,” he said in the Sept. 19 video.

“I apologize in advance if you as an individual are affected by it,” Watterson told employees. He didn’t offer any details on the pending moves.