US Olympic men's hockey general manager dies unexpectedly

General manager of the U.S Olympic men's hockey team, Jim Johannson, passed away, just weeks before the start of the Pyeongchang Winter Olympics, USA Hockey announced.

He died in his sleep Sunday morning.

"We are devastated to announce that USA Hockey's Jim Johannson passed away early this morning. Our heartfelt condolences go out to his entire family. JJ will be greatly missed, but always remembered for his immensely positive impact both on & off the ice," a post on USA Hockey's Twitter handle read.

USA Hockey Executive Director Pat Kelleher said in a statement, the organisation is "beyond shocked and profoundly saddened" by the loss of 53-year-old Johannson, reports Fox News.

"As accomplished as Jim was in hockey, he was the absolute best, most humble, kind and caring person you could ever hope to meet," Kelleher said.

"His impact on our sport and more importantly the people and players in our sport have been immeasurable. Our condolences go out to his entire family, but especially to his loving wife Abby and their young daughter Ellie," he added.

Johannson started working for USA Hockey in 2000 after spending five years as the general manager of the Twin Cities Vulcans in the United States Hockey League. He was later promoted to assistant executive director of hockey operations in 2007.

"Jim's positive influence was enormous and will be felt for generations to come," Jim Smith, president of USA Hockey, said in a statement.

"He was widely respected across the world and his genuine nature helped advance our sport in so many ways. Today, we are a medal contender every time we put a team on the ice for international competition, and he played a major role in helping us get to that point. Our heartfelt condolences go out to his entire family. It's a sad day for all of us," Smith added.

He also was a member of the U.S. Olympic team in 1988 and 1992.

USA Hockey further said funeral arrangements are pending.