Manny Pacquiao has lined up his next opponent, announcing he is negotiating an upcoming fight with Amir Khan.

A date and location for the bout are still to be determined, but Pacquiao said recently his next fight would take place in the United Arab Emirates.

That was contrary to a supposed deal for the Filipino to defend his welterweight title against Australia's Jeff Horn in Brisbane in April.

That fight has fallen apart, Top Rank chairman Bob Arum told ESPN.com.

"The Australian deal is not going to happen now because Manny is trying to get a fight done in the United Arab Emirates and the people there favour him fighting Amir Khan," he said.

Arum, who promotes Pacquiao, said a fight with Khan will take place "maybe in April or maybe June, but not May".

Pacquiao, 38, last fought in Las Vegas on November 5, defeating Jessie Vargas to reclaim the welterweight world title. 

Khan, 30, has not fought since May 2016 - a sixth-round knockout loss to Canelo Alvarez.

A potential card with Brit Khan in the UAE has drawn an offer for $38million, Arum said, but there is still some skepticism over whether a deal gets done.

"Whether it will happen or not I just don't know because they have to come up with a large amount of money," he told ESPN.

"Manny seems to believe they will come up with the money. I have some reservations whether it will happen or not.

"If the money comes up I will aid and abet the fight happening. But right now I'm holding my powder. I don't really know."