USA Gymnastics (USAG) has confirmed its entire board will resign following a demand from the U.S. Olympic Committee (USOC) in the wake of the sport's sex abuse scandal.

The USOC sent a letter to USAG on Thursday, calling for a host of measures to be taken after ex-USAG and Michigan State Athletic physician Larry Nassar was sentenced to 40 to 175 years in prison for sexually abusing young athletes under his care.

More than 150 women have accused Nassar of sexual abuse, including Olympic champions Aly Raisman, McKayla Maroney, Gabby Douglas, Jordyn Wieber and Simone Biles.

USOC CEO Scott Blackmun wrote: "The shocking and tragic stories surrounding Larry Nassar's years-long abuse of vulnerable athletes are now well known to all of us and the recently concluded Nassar sentencing hearings served to drive home the impact on individual victims in a way we will never forget.

"We must take further action to ensure that it cannot happen again.

"While the USOC encourages USAG to think and act broadly on reforming its culture, we also believe that reform must start with an entirely new board."

A subsequent USAG statement read: "USA Gymnastics completely embraces the requirements outlined in the Jan. 25, 2018 letter from the United States Olympic Committee and appreciates the opportunity to work with the USOC to accomplish change for the betterment of our organisation, our athletes and our clubs.

"We understand that the requirements imposed by the letter will help us enhance our ability to build a culture of empowerment throughout the organisation, with an increased focus on athlete safety and well-being.

"Our commitment is uncompromising, and we hope everything we do makes this very clear."

The USOC have set USAG a deadline of February 28 to put an interim board in place, while a new non-interim board must be filled within 12 months.

USAG's status as the sport's national governing body had been in doubt had the organisation not complied with the USOC. 

Other guidelines outlined in the letter to USAG from the USOC are:

- Within three months, all USA Gymnastics staff and board members must complete SafeSport training offered by the U.S. Center for Safe Sport.

- A comprehensive ethics training unit must be completed by all staff and board members within the next six months.

- USA Gymnastics must co-operate with the independent investigation into whether anyone knew about athlete complaints of Nassar’s abuse and didn't report them.

- At each of its meetings, the board also must "substantively discuss" how the federation is progressing in implementing 70 recommendations made by former federal prosecutor Deborah Daniels. Her review of USA Gymnastics found a "complete cultural change" was needed.

Michigan State athletic director Mark Hollis also announced his retirement on Friday.

"It's been an absolute honour to guide the athletic department for the last decade. That being said, today I am announcing my retirement," Hollis said in a statement.

"This was not an easy decision for my family, and you should not jump to any conclusions based on our decision - listen to facts. I am not running away from anything, I am running toward something. Comfort, compassion and understanding for the survivors and our community; togetherness, time and love for my family."