Novak Djokovic confirmed the partnership with Andy Murray as his coach will continue "indefinitely".

Three-time major winner Murray started working with his long-time playing rival on a trial basis at January's Australian Open, where Djokovic reached the semi-finals but was forced to retire with a hamstring injury.

After his Melbourne exit, the 24-time Grand Slam champion said he and Murray would need to "cool off" before discussing the future.

However, speaking before his defeat by Matteo Berrettini in the first round of the Qatar Open, Djokovic confirmed Murray will return to his coaching team.

"I expressed my desire to continue the collaboration with him so I am really glad he did accept," Djokovic, 37, told the ATP Tour's in-house media channel, external.

"It's indefinite in terms of how long we are going to work together but we agreed we are going to work most likely in the [United] States and then some clay-court tournaments and see how it goes after that."

Murray, who retired in August last year, took a surprise coaching role with Djokovic's team in late November.

"It was exciting for the whole tennis world and also for us to be in different roles together on the same side of the net," Djokovic added.

"He has a unique perspective on my game - he has played me, he has played all the current best players in the world in my opponents."

Serbia's Djokovic is aiming to win a 25th major, which would put him clear of Australia's Margaret Court in terms of all-time victories.

The next major tournament is the French Open, which starts on 25 May.

Berrettini beats Djokovic for first time

Later on Tuesday, Djokovic fell to a 7-6 (7-4) 6-2 defeat by Italy's Berrettini.

World number seven Djokovic was playing his first singles match since retiring from his Australian Open semi-final against Alexander Zverev.

"I didn't have any pain or discomfort in that sense. I was outplayed by just a better player today," said Djokovic.

Berrettini, 28, took control of the first-set tie-break before breaking early in the second set and seeing out the victory on his second match point.

It was his first win over Djokovic, who beat him in the final at Wimbledon in 2021, in five attempts.

"It's something that I've been looking to do," said Berrettini, who was named ATP Comeback Player of the Year in 2024 after winning three titles following his return from a lengthy injury spell.

"I played against him in the most important tournaments on Tour, had the honour and the pleasure to play against him. I wish I could have won one of those matches as well."

Berrettini will face Tallon Griekspoor in the second round of the ATP 500 event.