WBO welterweight champion Terence Crawford will take on Amir Khan in either New York or Las Vegas on April 20 – with their world title fight announced in London on Tuesday.

American Crawford, 31, is unbeaten in 34 professional fights, with 25 knockouts, and is considered to be one of the world’s best current pound-for-pound boxers.

British boxer Khan – one year Crawford’s senior – has won 33 and lost four of his 37 pro bouts, with 20 knockouts.

A venue has yet to be finalised, but the fight will either take place at Madison Square Garden in New York or at the MGM Grand in Las Vegas.

Khan turned down a clash with British rival Kell Brook to take the fight.

Crawford’s promoter – boxing legend Bob Arum – said his fighter is the best welterweight he has seen since former five-weight world champion Sugar Ray Leonard.

Watch what the two men had to say here.