Khan had been holding out for a big-money fight against Floyd Mayweather but the undefeated Michigan boxer has opted to take on Manny Pacquiao in a Las Vegas mega-fight in May.
The bad blood between Khan and Brook has been simmering since they sparred as team-mates in the England squad with Khan repeatedly claiming that Brook is simply not on his level.
Brook???s promoter Hearn is eyeing a bout between the welterweight pair this summer but warned Khan he could miss out on a shot at Brook???s IBF strap if he does not act fast.
The Matchroom Boxing supremo told Sky Sports News HQ: ???I???ve met with some representatives from Team Khan recently and obviously he was waiting, quite rightfully so, for the opportunity to fight Floyd Mayweather.
???But that is now not happening and I think obviously the fight with Kell Brook makes sense. It would be a massive fight for British boxing it carries a world title. Amir is confident that fight will happen but we want it sooner rather than later.
???Brook-Khan for me is just a natural fight and we can???t wait for Amir. We are going to be looking at Marquez, we???re looking at Maidana, even the winner of Mayweather against Pacquiao, because the bottom line is with those two fighting there will only be two world champions in that division. That???s either Pacquiao or Mayweather and Kell Brook, so it???s a chance to fully unify the division.
???It???s frustrating because Khan is the fight that we all want. We feel like the nation wants it as well and really, there is no reason why that can???t happen next.???