Dressed as a hitman, Oleksandr Usyk opened a briefcase, removed a photograph and walked over to Tyson Fury to get his heavyweight rival to sign it.

The picture was of Fury receiving a big left hand to the jaw from Usyk during their May 19 fight in Saudi Arabia when the Ukrainian won by split decision to become the world's first undisputed heavyweight boxing champion in 24 years.

"Nice one," Fury said after penning his signature.

In a news conference of few words in London on Wednesday, it was the actions and appearance of Usyk that stood out as the two fighters attempted to drum up publicity for their Dec 21 rematch back in Riyadh.

Usyk appeared to come as Agent 47 from the video game Hitman — dressed in a suit, red tie and black gloves and carrying a suitcase.

"It's just a character," he said in one of his longer answers in the news conference.

Did he need to do anything differently in the rematch, Usyk was asked. "No," was the reply.

What was he surprised by in the first fight? "I don't remember," Usyk said.

Asked if he had a message for Fury, Usyk said: "No."

Fury went on to mimic Usyk's one-word answers, though earlier gave a more detailed response about what he expected to happen in the rematch, when there will be three belts - WBA, WBO and WBC - on the line. In May, Usyk also won the IBF title but had to vacate it in June.

"I have to be a little more focused, a little more smart to get the victory," Fury said.

"All I can do is prepare well, train hard, eat well, go to bed early, wake up early, listen to people around me. And the rest is in God's hands.

"I believe it will be my time this time. I believe all things that happen, negative or positive, are lessons. We must learn from them."