However, the 31-year-old is not overlooking Samuel Vargas, who he faces in Birmingham on Saturday in his first bout back in the 147lb welterweight division since 2015.
Victory at the Birmingham Arena could be a big stepping stone for Khan towards a huge stadium clash in his next fight.
The Bolton boxer thought he had landed the Pacquiao fight a few years ago but it never came to fruition.
Promoter Eddie Hearn would prefer to see Khan face one of his other Matchroom fighters – long-term rival Brook in what would also be a huge bout.
However, Khan wants the multi-weight world champion from the Philippines as he feels victory over Pacquiao would define his career.
“Who would I rather face next? Pacquiao, definitely,” said Khan.
“I’d love the Manny Pacquiao fight. I think that’s going to be the defining fight – that is going to put me where I need to be in boxing. If I beat Manny Pacquiao that would put me where I want to be.
“He is a legend of the sport and I want to fight a legend. It would be the biggest fight of my career.”
Asked if chasing the Pacquiao fight again is because he sees it as pivotal to cementing his own legacy, Khan said: “It’s not about that. I just want to fight the best and beat the best out there and be remembered as a great fighter.”
“What I’ve done in British boxing is what most fighters have never done before. I’ve won world titles, headlined in Vegas, fought the best out there. I’ve done it all so what’s left, win another world title? Something I’ve already done.
“First though, I’ve got to get the win on Saturday and I am not looking beyond Samuel Vargas.”
Colombia-born Vargas, 29, is confident of derailing Khan’s plans and causing an upset, believing the Briton is past his best and “damaged” by the devastating knock-out defeat against Saul ‘Canelo’ Alvarez in 2016.
“There is no doubt in my mind I will be victorious on Saturday night,” said Vargas. “I don’t care how I do it, whether it’s by knockout, going the distance or I break his ribs – I don’t care.
“I think he’s an old man and he’s been damaged a lot.”
Khan was unperturbed, though, insisting there is a gulf in quality between the two fighters.
“I’m glad he’s confident as he’s making the fight more interesting,” Khan said. “To be honest, I don’t know much about him. But I’ve seen him fight and he’s not on the same level as me.
“He’s not as good as the guys I’ve beaten in my career and nowhere near as good as the sparring partners I’ve had so he’s got no chance. I’m a better fighter, he’s not on the same level.”