Citing a lack of motivation, chess world number one Magnus Carlsen on Wednesday announced that he would not defend his world championship title in 2023, but stressed that he was not retiring from chess.

"I am not motivated to play another match... I simply feel that I don't have a lot to gain. I don't particularly like it," Carlsen said in the first episode of his podcast "The Magnus Effect".

Carlsen has repeatedly hinted that, bored with a title he has held for nearly 10 years, he may give up his throne without a fight.

The 31-year-old crushed Russian Ian Nepomniachtchi 7.5-3.5 in his fifth straight victorious title match last December.

"Although I'm sure a match would be interesting for historical reasons and all of that, I don't have any inclination to play and I will simply not play the match," Carlsen told the podcast released Wednesday.

Carlsen said he had met with representatives from The International Chess Federation (FIDE) to inform them of his decision in Madrid in connection to the Candidates Tournament -- which decides who gets a chance to challenge the world champion.

"We had a small discussion. They had some suggestions, some of them I liked, some of them I did not, but ultimately the conclusion stands," he added.

Carlsen added that he had thought about the decision for over a year, "since long before the last match".

Magnus Carlsen won his fifth world title in 2021
Magnus Carlsen won his fifth world title in 2021 AFP

"His decision not to defend his title is undoubtedly a disappointment for the fans, and bad news for the spectacle. It leaves a big void," FIDE President Arkady Dvorkovich said in a statement commenting on Carlsen's announcement.

"But chess is now stronger than ever -- in part, thanks to Magnus -- and the World Championship Match, one of the longest and most respected traditions in the world of sports, will go on," Dvorkovich added.

With five wins and nine draws, Nepomniachtchi won the Candidates tournament, but with Carlsen bowing out, "Nepo" will face runner-up Ding Liren of China for the title.

Carlsen first became world chess champion in 2013 when he defeated Indian grandmaster Viswanathan Anand.

A sixth successful title match would have brought Carlsen level with German Emanuel Lasker, the champion from 1894 to 1921, and Soviet Mikhail Botvinnik.

Botvinnik held the title between 1948 and 1963, although during that time he twice lost and regained the title and his two successful defences came in drawn matches.

"Overall I feel like it's my time to go from the World Championship matches. I don't rule out a return in the future but I wouldn't particularly count on it," Carlsen said.

But Carlsen also stressed that he was not retiring from the sport.

"Just so there is no ambiguity here, I'm not retiring from chess, I'm still going to be an active player."

He would next be heading to Croatia to play in the Grand Chess Tour, and then to India's Chennai to represent Norway at the Chess Olympiad.