Enlow had been USA Shooting's chief executive since December 2017 when he took over the role from the retiring Robert Mitchell.

"We are very appreciative of Keith's dedication, leadership and passion in leading us through a key transitional moment in this organisation's history," said Whittenburg.

"He fought hard to make sure we were headed in the right direction as an organisation and we're in a much better spot today than we were when he began. 

"Despite his departure, the mission and efforts remain unchanged with 13 months until Tokyo 2020 and we'll remain focused on supporting our athletes in their quest to achieve their Olympic and Paralympic dreams."

The organisation's Board of Directors will go ahead with their scheduled quarterly meeting on June 25 as part of the USA Shooting National Championships for Rifle and Pistol in Fort Benning, Georgia.

A leadership transition plan will be added to the agenda following Enlow's departure but with long-time sports executive Bob Gambardella recently taking on chief of operations duties, the organisation believes it is well positioned going forward.

During his time as chief executive Enlow used his knowledge of the industry to stimulate revenue generation while engaging donors, sponsors and other strategic opportunities, USA Shooting said.

Following pistol funding cuts by the United States Olympic Committee (USOC), he developed a Pistol Dreams Committee which brought together industry leaders and a relocation of resources which ensured athletes could continue to train and compete.

After leaving USA Shooting, Enlow said: "I am very thankful for the opportunity that was given to me to help transform USA Shooting, and I am proud of the stability and continuous improvements that were made.

"I have truly enjoyed my time here with our athletes, staff, the USOC, and the Board, and I believe the experience has taught me much about the sport and America's shooting team. 

"I wish the team nothing but success in their preparation for Tokyo and beyond.

"I know they are capable of great things."

In November USA Shooting faced criticism after signing a deal with a firearms auction website which allegedly hosted sales of "Holocaust memorabilia".

In response, a USA Shooting spokesperson told Newsweek: "Our relationship with Gunbroker in no way signifies our approval of these items, just as we don't approve of every item or the editorial on the websites and social media platforms that we use to promote our sport.

"We use Gunbroker.com with a very specific purpose of hosting auctions of donated firearms to raise money for our team and athletes. 

"That is the current partnership arrangement."