World heavyweight boxing champion Oleksandr Usyk will defend his titles in a rematch with Britain's Anthony Joshua in Jeddah, Saudi Arabia, on August 20, promoters announced Sunday.

Ukraine's Usyk defeated then WBA, IBF and WBO champion Joshua by a unanimous decision in London in September last year.

"Champion Oleksandr Usyk will put his IBF, WBA, WBO and IBO world titles on the line against Anthony Joshua in the coastal city of Jeddah, Kingdom of Saudi Arabia on Saturday August 20," said a statement issued by promoters Matchroom Boxing.

No sooner had Usyk defeated Joshua 117-112, 116-112 and 115-113 on the judges' scorecards in London then a rematch clause was activated.

Russia's invasion of Ukraine in February, however, placed a question mark over when former undisputed cruiserweight champion Usyk would be back in the ring.

The 35-year-old returned to Ukraine to fight for his country but was given special exemption from military duty in order to prepare for this bout.

"I have a goal, with the help of the Lord I will complete my mission!", said Usyk in Sunday's statement from Matchroom.

Joshua, 32, has made changes to his coaching staff as he bids to be crowned world heavyweight champion for a third time.

Rob McCracken, the trainer who oversaw 2012 Olympic champion Joshua's rise from the amateur ranks, is no longer a member of the team, with Robert Garcia added to the corner to work alongside the already-installed Angel Fernandez.

August's fight will be Joshua's second bout in Saudi Arabia after he regained his world titles with a points win over Andy Ruiz Jr in Riyadh in December 2019.

Joshua labelled his recent career as a "roller-coaster", adding: "Fighting championship level back to back has had its pros and cons, but I decide every day to get stronger, to learn from my experiences and grow.

"A happy fighter is a dangerous fighter and I am the happiest and most motivated I have been."