Tyson Fury vs Oleksandr Usyk heavyweight title fight to take place in Riyadh in February
Britain's Fury is the WBC world champion while Ukrainian Usyk holds the WBA, WBO, IBF and IBO belts. Both have unbeaten records.
Contracts were signed in September for a proposed December 23rd date, although that was never confirmed and slid after Fury's near defeat to former UFC champion Francis Ngannou in a non-title bout in Saudi Arabia on October 28th.
Heavyweight boxing's last undisputed world champion was Britain's Lennox Lewis in 1999, but this time, four belts are up for grabs for the first time.
After the announcement, a tense confrontation occurred between the boxers during a press conference, resulting in their eventual separation.
"You're welcome to be sharing a ring with the future undisputed heavyweight champion - me," Fury said.
"You know what's coming, you're getting smashed to pieces. You're fighting the best British heavyweight there's ever been."
Usyk responded that he did not listen to anything Fury says, focusing on the match.
"When the Lord gives me Tyson in my hands, I will do my job," he said.
Later, Usyk said that he saw the match as a chance to give back to all those who supported him.
"It's a big opportunity, (being) undisputed, for my family, country and people who now defend my country," he said.