National Football League teams will be required to hire at least one minority offensive assistant coach as part of a drive to boost diversity across the sport, NFL owners announced Monday.

The measure, which comes amid recent controversy over the NFL's record over the hiring and promotion of minority coaches, will be in place for the 2022 season.

The initiative was adopted and passed by all 32 clubs during the NFL owners' annual meeting in Florida.

Pittsburgh Steelers owner Art Rooney II said the measure reflected the increasing tendency for head coaches to come from the ranks of offensive assistants.

"It's a recognition that at the moment, when you look at stepping stones for a head coach, they are the coordinator positions," he told ESPN.

NFL commissioner Roger Goodell says the league's record on appointing minorities to top coaching jobs is 'unacceptable' NFL commissioner Roger Goodell says the league's record on appointing minorities to top coaching jobs is 'unacceptable' Photo: GETTY IMAGES NORTH AMERICA via AFP / Katelyn Mulcahy

"We clearly have a trend where coaches are coming from the offensive side of the ball in recent years, and we clearly do not have as many minorities in the offensive coordinator (job)," added Rooney, the chairman of the NFL's Diversity, Equity and Inclusion committee.

NFL Commissioner Roger Goodell told clubs last month the league's record of hiring minority candidates to head coaching jobs had been "unacceptable."

It came after sacked Miami Dolphins coach Brian Flores accused the NFL and certain clubs of racist hiring policies in a lawsuit.

On Monday, Goodell provided details of a new advisory committee made up of outside experts that will study diversity hiring practices before reporting back to the league with recommendations.

"We've worked for years and made progress in many areas to ensure that staff and leaders in our office and at our clubs reflect the racial and gender makeup of America, but we have more work to do, particularly at the head coach and front-office level," Goodell said in a statement announcing the six-strong committee.

"This esteemed group's work will help us build a more inclusive league. We look forward to their recommendations -- and to continuing our conversations with other outside experts, community and civil rights leaders... to make our efforts and those of the clubs more effective so that real and tangible results will be achieved."