That's according to the Filipino's promoter Bob Arum who claimed, despite only the location of fight left to decide, that plans for one of the most anticipated fights in years are "dead".
The two fighters had announced the deal at the end of February with a venue in the United Arab Emirates thought to be the preferred option for both.
But, speaking to ESPN, Arum revealed the April 23 showdown is no longer on the cards.
"(Pacquiao's adviser) Michael (Koncz) is on his way back to meet with Manny but it's kaddish for the UAE deal. It's dead," he said.
"I'm talking to him about another proposal for another fight, not Khan. Khan won't be Manny's next opponent."
Pacquiao, 38, who currently holds the WBO welterweight title, tweeted last month: "Negotiations between team Pacquiao and team Khan have come to terms for the April 23 bout as this is what the fans wanted."
Khan had tweeted in February: "My team an I have agreed terms with Manny Pacquiao and his team for a super fight #pacquiaokhan #April23rd."
Pacquiao continues to be trained by Freddie Roach but Khan left the American in September 2012 and is now under the tutelage of Virgil Hunter.
Khan's last fight in May 2016 was at 155lbs, when he challenged Mexico's Saul Alvarez for the WBC middleweight title but lost in six rounds.
He has also long spoken of fighting in the UAE, where he has a southern Asian fanbase, and of his desire to test himself against either Pacquiao or Floyd Mayweather, two of the finest fighters of the modern era.
The 30-year-old previously said: "When I sparred with Manny he was dangerous. They were hard rounds and I knew then that one day I would fight him. I have been ready for a long time."Reuse content