Mike Tyson said he was fit and ready for his November 15 fight against Jake Paul as the two American boxers held a joint news conference in New York City.

The match was originally scheduled for July 20 but was postponed after former world heavyweight champion Tyson, 58, had an ulcer flare-up that forced some resting time.

"Iron Mike", who has a 50-6 record with 44 knockouts, was one of the most feared heavyweights in history but has not fought a professional fight since 2005.

When asked why he returned to the ring so long after retirement, Tyson's response was clear: "Because I can. Who else can do it but me? We have a YouTuber fighting the greatest fighter ever to live."

"He may have been in the ring with people who have the same intentions, but the actuality, no.

"As soon as I catch this guy it's going to be totally over, he is going to run. He is gonna run like a thief."

Paul, who was booed and heckled by the crowd, claimed he would put Tyson to sleep.

"I am here to make $40 million and knock out a legend," Paul said.

"I love Mike and I respect him but we are not friends anymore until November 15."

When asked if he was afraid of being in the ring with Paul, Tyson replied sarcastically: "I am terrified."

YouTuber-turned-boxer Paul, 27, is 31 years his junior and has a 10-1 boxing record.

The fight will be streamed live globally on Netflix and will take place at the 80,000-seat AT&T Stadium in Arlington, Texas, home of the Dallas Cowboys.