Amir Khan believes that a bout with Floyd Mayweather Jr for a substantial purse will happen in the next "six to nine months" and that a clash that could become the richest fight in history would take place in the US – probably in Las Vegas.

Khan, who is the WBA and IBF light-welterweight champion, said he is "99%" certain to fight Lamont Peterson next on 10 December, probably in New York or Washington. Asked if Khan-Mayweather could happen after that bout he said: "It can. And listen I'm ready to fight [him]. I can see a lot of things in my armoury that would beat Floyd – he will take a lot of shots and he will get beat. Floyd Mayweather is beatable – I think definitely he's beatable. The fight will happen definitely – it'll happen within the next nine months – six to nine months.

"Because of the money [involved] it could never be here [the UK], there's too much money, so much money in America. America is 50 times bigger than England so imagine how much popularity we'll get fighting over there."

Khan said that as he and Mayweather have similar styles the contest could be a technical showdown. "The two styles? I've got a slick style, fast hands, he's also got good hands, we've both got power, I think it'll be more of a technical game, thinking about it: who lands the right shots at the right time," he said.

Mayweather had said he would only take on Khan if he first beat one of his own fighters, Jessie Vargas, but he later admitted that this was just a joke to help promote the 22-year-old.

Depending on the potential timing of the clash with Mayweather, who took his unbeaten record to 42 by knocking out the WBC welterweight champion, Victor Ortiz, in Las Vegas at the weekend, Khan may fight once more beforehand, potentially in the UK at welterweight. The 24-year-old said: "What I want to do is in March time bring a big fight over here. That's what I'm looking for, or maybe fighting one of the UK opponents at 147 [pounds], moving up a weight."

Khan backed Mayweather following his controversial knockout of Ortiz, which occurred at the close of the fourth round when the 34-year-old landed a right as his opponent appeared to be apologising to the referee, Joe Cortez, for butting Mayweather. "It was a good performance because you have to remember with the adrenaline pumping through your body after being head-butted as well is going to kind of piss you off," Khan said. "What Mayweather did was just come back with a shot as soon as the referee said box on.

"He hit Ortiz regardless if he was looking at him or not. Why was he looking at the referee? It's a rule in boxing, you never take your eye off your opponent and that's what Victor Ortiz did. Another rule is to defend yourself at all times, which is mentioned to fighters before they get in the ring and just before the bell goes. So it's one of those things. He caught Victor so clean even when he got caught with the first left hook, Victor should have put his hands up at least or maybe held him, whereas he looked at the referee straightaway.

"If that had happened to me I would have thought: 'It is my own fault.' Victor is probably thinking that it's his own fault. It's not Floyd's fault."

Regarding the meeting with Peterson, a 27-year-old American who has lost one and drawn one of his 31 outings, Khan said: "It's on 10 December, that's been confirmed, 99%. We're looking at either Washington or New York or Montreal but I think it's going to be a little bit cold in Montreal. But it will be somewhere in [North America]."

• Amir Khan is an ambassador for the Non-Violence Foundation. For details of the Knot Violence campaign, click here.