But the 33-year-old will not be taking part in next autumn's championships in Edmonton - and is already planning a career away from the track.

He said: "This year will be my last - I'm tired."

Johnson has an impressive record in the event over the years. He has won six individual golds and holds world records in the 200m (19.32 secs) and 400m (43.18secs).

Explaining that his career has all about achieving goals, rather than satisfying the demands of the public, he continued: "I've already begun making the transition.

"I'm doing TV for NBC and I'll be working on both the winter and summer Olympics. I'll be doing lots of other things as well."

Johnson - in Britain for the World Sports Awards, which are being held at London's Royal Albert Hall on Tuesday - has not ruled out a return to these shores later in the year, to give his British fans a proper send-off on the track.

"Perhaps I'll visit the UK in my farewell year but it depends on how things go," he said. "I'm figuring out how best to negotiate my season."

Johnson added: "Over a decade I did a lot of things that no-one had even thought of before and I am proud of that.

"How I want to be remembered is as a consistent performer over a long period of time."

Johnson believes his finest moment to have been the 1996 Olympics on home soil in Atlanta, when he added 4x400m gold to a 200m and 400m double.

He said: "It was something I was working on for many years and I was successful.

"It was the biggest challenge in my career and I am very proud I pulled it off."