MANILA, Philippines - Former light-welterweight champion Amir Khan is not giving up on his dream of facing undefeated American Floyd Mayweather Jr., despite suffering a serious career setback when he lost to Lamont Peterson last Saturday in Washington DC.

In one of the big upsets of 2011, Khan lost his International Boxing Federation (IBF) and World Boxing Association (WBA) title belts to Peterson in a contested split decision. Khan was fighting in Peterson's home town of Washington DC and has complained about the referee during the fight.

Despite the loss, Khan remains hopeful that he will still fight Mayweather, only at a later date than he originally expected. In previous interviews, Khan had declared that he would be ready to fight Mayweather by 2012.

"Instead of taking that fight with Mayweather in 2012, 2013 is going to be perfect," Khan told Boxing Scene. "This is only going to make me more mature, and make me a better fighter."

Khan and his team are pursuing an immediate rematch against Peterson, possibly in early 2012.

The British fighter was a massive favorite going into the fight against Peterson, and had repeatedly said he will move up to the welterweight division following his title defense to pursue bigger fights.

But with his shocking loss, Khan may have to stay at the light-welterweight level for a longer period.

"Maybe making me wait that couple more months will give me one more fight at 140-pounds, and then I'll move up to 147-pounds, take one fight at that weight," Khan said.

Mayweather, the current World Boxing Council welterweight champion, is planning to make his return to the ring on May 5, 2012. He is reportedly targeting a mega-fight with Khan's stablemate, Filipino boxing champion Manny Pacquiao.