LONDON -- Anthony Joshua has given Deontay Wilder a deadline of December to agree terms to face him on April 13.
The WBA-IBF-WBO world heavyweight champion floored Alexander Povetkin in the seventh round before following up to force the stoppage at Wembley Stadium.
Joshua (22-0, 20 KOs), 28, is due to make a seventh title defense back at the same London venue on April 13 and wants a deal made with Wilder before the American has his next fight.
WBC titleholder Wilder (40-0, 39 KOs), 32, has signed to face Joshua's British rival Tyson Fury on Dec. 1 at what is expected to be an American venue.
"I will knock them down one by one, but people will have to be patient," Joshua said. "April 13 is booked so whichever one wants to step up and take the challenge I'm more than willing to fight them. Whichever heavyweight is serious, get on the phone to [promoter] Eddie [Hearn] and make a deal.
"I've got no interest [Wilder or Fury] in who wins. I'm not really swaying towards Wilder or Fury. I will start training for a fight in early January. There's a lot of room for all of these heavyweights. If Wilder isn't serious there are other people out there. When he's ready, we're ready."
Wilder and Joshua could not agree terms, after both parties had made offers, to meet in a four-belt world heavyweight title fight to decide the undisputed champion.
"We're in the same division, we're in the same era, it would be silly not to fight," Joshua said at a news conference. "I don't want to wait until December for him to win that fight and start negotiating. I start training for my next fight in early January, so I want to know who I'm facing this side of the year.
"I would fight all of them. Wilder next, no problem. Hopefully we can get that deal signed and sealed by December. I would fight Fury if he's ready."
Joshua's promoter, Eddie Hearn, would prefer Wilder over Fury (27-0, 19 KOs), 30, and says he wants a deal agreed by Dec. 1.
"We're not willing to wait until December," Hearn said. "We can wait until December to see but a deal must be done well in advance of that. We have been back and forth with various stuff. The offer that was made to us had no real substance. It will look like absolute peanuts when this fight gets made.
"I want Deontay Wilder to win that fight because it's the biggest in the world," Hearn said. "It could be one of the biggest fights in all time. Wladimir Klitschko [against Joshua in April 2016] was the biggest in British history, but this one would eclipse that. We will negotiate the fight now. We're not waiting until December. If they want the deal we can make it happen for April. We will have someone else in place for April too. If Fury wins, it's not what we want because Wilder will have a rematch clause. In terms of April, if we want the fight to happen then, Wilder must win. Tyson Fury is the most unentertaining fighter I've ever seen. He's never been in a good fight, apart from one against Steve Cunningham where he got knocked down."
Povetkin (34-1, 24 KOs), 39, was impressively aggressive and consistently dangerous with left hooks and overhand rights. But Joshua gained some composure after some worrying moments in the early rounds, and when Povetkin was shook by a right hand, it began an avalanche of big punches from the champion.
"At this level it's never going to be easy," Joshua said. "It may have took seven rounds, 10 rounds or 12 rounds, but ultimately I'm going to be victorious because I know how to dig in.
"Instinct told me he was hurt and it was time to get him out of there."