Ryanair Holdings PLC pilots campaigning for unionization amid a staffing crisis that's led to the cancellation of 20,000 flights have been offered financial backing from American Airlines Group Inc.'s cockpit-crew association.

The Allied Pilots Association has offered to support Ryanair crews in forming a union or joining an existing body such as the Irish Air Line Pilots' Association, according to Daniel Carey, president of the U.S. group, who met with the Dublin-based carrier's employees last week in the city. The APA is aiming to stem the hiring of staff on unappealing contracts through outsourcing firms.

"We've been following the Ryanair model and we don't want indirect employment to come to America," Carey said, adding that Fort Worth, Texas-based APA is open to pitching in with communication expertise, IT support, additional manpower and financial assistance.