UFC great Georges St-Pierre has announced his retirement from MMA but the Canadian star stopped short of closing the door completely on a return to the octagon.

The 37-year-old called time on his career on Thursday amid fears the sport was taking its toll on his body, having become a household name after posting a record of 26 wins from 28 bouts.

He revealed he had tried to schedule a fight with lightweight champion Khabib Nurmagomedov, who he called the best fighter in the sport, but negotiations failed.

Asked whether he would ever consider a comeback, St-Pierre said: "I don't know where I will be mentally in a few months. I don't know. For me, it's retire now. That's all I'm thinking about.

"If ever something happened or [UFC president] Dana [White] called me back and there's something interesting, we'll see.

"Like a movie scenario, 'Oh he's coming back' – we’ll see, but right now I'm not thinking about it. I'm out.

"I'm always going to be training. For me, it's just an au revoir, it's just a goodbye. I'm not dead.

"I see athletes get fat after retirement, that's not going to be me. I look better in training now than I did years ago."

St-Pierre explained the breakdown in talks over a bout with Nurmagomedov were not the key factor in his decision to retire, underlining the physical impact of fighting at the highest level.

"In my case, it's not really the head trauma," he said. "It's more the stress that has been built up over years and years and years. That takes a lot out of me.

"I feel disappointed that the Khabib fight did not materialise. But in a way not too much, because I don't have the same anger as I used to.

"There will always be another fight. It's always about what's next."

St-Pierre, who turns 38 in May, holds the record for most welterweight title defences in UFC history with nine and is widely considered one of the finest competitors in the sport's history.

He has not fought since his win over Michael Bisping at UFC 217 in November 2017.