The world's number one chess player, Magnus Carlsen, has said he will return to a major chess competition after the sport's governing body agreed to relax its dress code.

Carlsen quit the World Rapid and Blitz Chess Championships in New York on Friday, where he was defending his title, when he was told he could not continue playing while wearing jeans.

The International Chess Federation (Fide) later said that it would relax its dress code to allow for "elegant minor deviations" from its official list of acceptable attire.

The 34-year-old has since said he will return to the contest on Monday and will continue to wear jeans when he plays.

Carlsen, a five-time chess champion, was fined $200 (£159) last week for breaching the tournament's dress code.

He said he had been wearing jeans for a lunch meeting, and "didn't even think about" swapping them for a different pair of trousers when heading to the tournament.

He had already played a few rounds wearing a shirt, a blazer, and jeans when he was told he had breached dress code regulations.

The grandmaster said he had offered to change his trousers for the next day, but was told he needed to change immediately, which he refused to do.

Carlsen then withdrew from the competition and said he would leave the city.

"Nobody wants to back down... I'll probably head off to somewhere where the weather is a bit nicer than here," he said.

Announcing the changes to its dress code on Sunday, Fide president Arkadi Dvorkovitch said: "The principle is simple: it is still required to follow the official dress-code, but elegant minor deviations (that may, in particular, include appropriate jeans matching the jacket) are allowed."

He said tournament staff will be required to help judge whether outfits fit the relaxed code, and added that he hoped players would not "undermine the festive mood" at the tournament on New Year's Eve by "abusing this additional flexibility".

In a social media post on Sunday, Carlsen said: "Oh, I am definitely playing in jeans tomorrow."

Fide had previously said its dress code regulations were designed to "ensure fairness and professionalism for all participants".

Carlsen is a high-profile figure in chess who has attracted some controversy in recent years.

The Norwegian became a grandmaster - the top title in chess - at the age of 13, and has long been considered a maverick in the chess world.

In 2023, he settled a long-running legal dispute after accusing an American rival of cheating.

Carlsen had made the accusation after he was unexpectedly beaten by 19-year-old chess prodigy Hans Niemann in a 2022 match.

Niemann denied the allegations and filed a $100m (£79m) defamation lawsuit against Carlsen, the website Chess.com and another US grandmaster.

Last August, Chess.com said the suit had been settled out of court, and that Carlsen now accepted Niemann had not cheated.