Twelve-times grand slam champion Novak Djokovic will miss the rest of the tennis season to recover from an elbow injury, the Serbian said on Wednesday.

The 30-year-old posted a video statement on Facebook in which he said he had decided to rest the injury which caused him to retire during his Wimbledon quarter-final against Czech Tomas Berdych earlier this month.

"I've made a decision to not play any competitions or tournaments for the rest of the 2017 season," Djokovic, down at number four in the world rankings for the first time since 2009, said. "It's a decision that had to be made."

Djokovic posted the video shortly before a news conference at which he explained his decision in more detail.

"I have been dragging this injury for the past 18 months and it has escalated in the last month or two," he told reporters.

"I had to make a radical decision. It was a difficult one but I had no choice and will now have time to heal my body.

"Surgery is not necessary, all the surgeons I have spoken to have not recommended that course of action and I was also keen to avoid it."

Djokovic has endured a dreadful 12 months on the court, losing all the grand slam titles he held simultaneously after winning the 2016 French Open, as well as the number one ranking.

He also split with his entire coaching team in May, having parted with Boris Becker at the end of last year.

Djokovic faces a big fall in the rankings but said he would be back for the start of next year.

"I will definitely play in the first week of next season," he said. "I have enough time to recover as the first tournament of 2018 is six months away."

"I now have to focus on healing my elbow as quickly as I can so I can get back to full training," he added.