Anthony Joshua insists he’ll be more focused and better prepared for his rematch with Andy Ruiz when they meet for the unified heavyweight championship on Dec. 7 in Diriyah, Saudi Arabia.

Joshua (22-1, 20 KOs) will be attempting to regain the WBA, WBO, IBO and IBF heavyweight championship belts he lost on June 1 when Ruiz (33-1, 22 KOs) scored a stunning seventh-round TKO over the heavily favored Brit at Madison Square Garden. A pudgy Ruiz was a huge underdog in the bout, but he dropped Joshua four times before the referee stopped it, making Ruiz the first heavyweight champion of Mexican descent.

“I did everything wrong,” Joshua said moments before a formal press conference Thursday in lower Manhattan to promote the bout. “It was me. I blame myself. But I’ll get it right.”

Joshua offered a few reasons why he was a flop in his American debut as champion. There was more talk that week of potential bouts with Deontay Wilder or Tyson Fury than there was about Ruiz. Also, Ruiz’s short puffy build masked his hands’ speed and power. Ruiz was a late replacement for Jarrell “Big Baby” Miller, who was Joshua’s original opponent, but was pulled from the card after testing positive for a banned substance.

“I’m not hearing about another fight,” Joshua said of his current state approaching the upcoming bout. “I’m only hearing about Ruiz and

that’s a blessing. I know I’m getting ready to fight that wolf under sheep’s clothing. I’m preparing myself mentally for what’s about to come.”

New York was the second stop on a promotional tour that began the previous day in Saudi Arabia, where the fight will be held in a 16,000-seat arena. DAZN will live stream the fight. A rematch clause contained in the contract for the first bout gave Joshua’s camp the choice of venue, but after considering locations in the United Kingdom and the United States, both sides agreed on Saudi Arabia.

“This is a move into a territory that is not used to having a mega-event,” Matchroom Boxing promoter Eddie Hearn said. “All the eyes of the world will be on them and they want to be perfect. For Joshua, it’s a must-win fight. If Ruiz wins, he’s the biggest star in boxing.”

Joshua, a gold medal winner from England in the 2012 London Olympics, was among the biggest stars in boxing until he was pummeled by Ruiz. Unbeaten in his first 22 fights, Joshua looked good early, dropping Ruiz with a left hook in the third round. But Ruiz got up and rallied to drop Joshua in the same round before dominating and ending the bout in the seventh.

Since then, Ruiz has been on a celebration tour, while Joshua has tried to determine what went wrong. Along with all the talk about other opponents, Joshua said his demeanor was wrong, his neck was hurting and he didn’t follow his game plan.

“I don’t want to overcomplicate the situation,” he said. “In 22 out of 23 fights, the blueprint worked.”

Joshua said he planned to tweak some “lifestyle stuff” and is “sharpening the tools” he didn’t use in the first fight. He also said he wants to be “more slick” in the ring.

“It takes a true champion to make adjustments at a high level,” Joshua said.

The former champion looked far more serious Thursday than he did at any point during or after the first fight.

“In my short, 11-year career, I’ve seen a lot,” Joshua said during the press conference. “There are times I faced defeat as an amateur. If I stopped then, there would be no now. I lost in the world championship finals. If I stopped then, there would be no now. As long as I have breath in me, I’ll keep fighting for the passion of boxing and more so to be an ambassador of the sport. That’s where I feel I belong. I’m not gun-shy. I’m looking forward to getting my titles back.”