The WBA (Super), WBO and IBF champion defends his titles on Saturday against former cruiserweight champion Usyk.
A cordial press conference today gave way to an intense face-off before a handshake between the pair.
Joshua, 31, said: "I'm not an easy fight for anyone, I like fighting."
He added: "If you tell me I was fighting King Kong I would give it a go. This is my job.
"I wasn't on the amateur scene long enough to know much about Oleksandr, but when I turned professional I did a lot of research and I love the Ukrainian style and the Ukrainian people.