Boeing CEO Dennis Muilenburg said the aerospace company is having "ongoing conversations" with its customers about the costs and other issues regarding the prolonged grounding of its 737 Max jets.

Nearly 500 Max planes have been grounded across the globe since mid-March following two fatal crashes of the popular plane model over five months. Regulators pointed to a flaw in the plane's software as a contributing factor in the accidents. The pilots union for Southwest Airlines said earlier this month that it would seek reimbursement and compensation from Boeing for the Max's grounding.

"We're going to be working with all of our customers around the world to make things right, and I won't get into the details of those because that'll be done individually customer by customer," Muilenburg said in an interview with Mike Allen of Axios at the Aspen Ideas Festival on Wednesday. "But we have a mutual interest in helping our customers be successful." He didn't directly address the union's concerns.

Muilenburg said some of those conversations are around financial impact, but others could deal with plane delivery schedules to accommodate fleet changes caused by the grounding. His comments echoed statements Muilenburg made on Boeing's most recent earnings call.