There is danger lurking in Lamont Peterson, but also the sense of an ending.

To Amir Khan, the 27-year-old American with a reputation for being a courageous and awkward opponent represents confirmation that the ranks of the light-welterweight boxers can no longer contain his ambition or the range of his talent. When Khan takes to the ring in Washington DC on Saturday night to defend his two world titles, it will also be an attempt at a coronation.

Plans are fragile commodities in boxing, where money, power, ego and opportunism are constantly jostling for influence, but Khan intends to move up to welterweight, the division in which Manny Pacquiao and Floyd Mayweather junior are the undisputed kings. This is the status that Khan wants to reach – the pre-eminence of the all-time greats – and the contest with Peterson is a stage in his progression.

He should defend his WBA and IBF belts, but Peterson does carry a threat. He likes to fight at close quarters, hunched and strong, where his head can be damaging as he suddenly lunges forward and up; but he can also box slickly at range. As always, the menace that Khan brings into the ring lies in his speed. The fast hands, the quick footwork and the sleight of mind all lift Khan beyond the reach of most contemporary opponents.

"We've been working on some new techniques and I know exactly what to do against Lamont Peterson," he says. "We know he's tricky and he's strong; so we've covered all areas for this fight. He might be behind, but he'll always keep trying and trying. So he's always going to be in front of you. It's going to be a tough test for me."

Khan insists he will never fight Pacquiao, who has become a friend since they started to train together under Freddie Roach in Los Angeles, but rumours still persist that a contest with Mayweather will happen in 2013.

If Lee McAllister, the Aberdeen boxer, wins the European light-welterweight belt in February, he would like to challenge Khan, but even although the world champion says, "we've got a plan, but I've never backed down from anybody", the likelihood is Khan will move on to more high-profile bouts. He says: "I make the weight quite easily, I'm dedicated and disciplined. The only reason I'm moving up to 147 is that there are more challenges there. It's going to be a motivation when I train knowing that I've got tougher guys in front of me who can punch harder.

"In the next 12 months, I'll hit my peak. If we can get the right fights. I'd maybe finish my career at light-middleweight. I've got the height, the body frame, we'll need to see how I grow into that weight."

Khan was friendly with Gary Speed, the Wales manager who took his own life last weekend, having met the former Bolton player when he worked out at his local club's training ground. Khan lives a demanding existence himself, but finds training, in its routines and its physical and mental commitments, provides an important release, while his family offer constant support.

"My training keeps me calm," he says. "It takes away the stress. At times you do feel tired and depressed. That's when your close ones are there for you, supporting you and making sure you're OK."

o Matthew McAllister believes he will be a better fighter having learned from the errors made by his elder brother, Lee. The pair train and spar together, and Matthew will be on the undercard when his brother challenges Denis Shafikov for the European light-welterweight title in February.

"He's an inspiration," the Aberdeen fighter said. "I learn a lot from the mistakes he's done, training, his fights, diets, everything."

Khan v Peterson is live on SKY HD1 on Saturday