If Manny Pacquiao's next opponent is not Floyd Mayweather Jr., put Amir Khan on the top of the list of possibilities for his next bout.

Pacquiao adviser Michael Koncz told Yahoo Sports by telephone from London on Friday that he'd met with Khan and members of Khan's team about a potential pay-per-view fight between the two later this year.

Pacquiao traveled to London along with his wife, Jinkee; Koncz; Chavit Singson, a former governer in the Philippines, and several others to meet Prince Harry. The group had dinner with the prince at Buckingham Palace on Thursday and another shorter meeting on Friday morning.

After that, Koncz told Yahoo Sports the group met with Khan's team at Fitzroy Lodge Amateur Boxing Club in London.

"We've had previous discussions before I came here and [Khan's team] had discussions with Golden Boy, as well," Koncz said. "Don't take this as us slamming the door on Floyd because we're not. But we're not going to sit around and find ourselves in this position in two weeks, waiting for an answer from him. So we're just making alternative plans in case we can't get the Mayweather thing done, and Amir is a possibility."

Koncz said there is interest in holding a potential Pacquiao-Khan bout in either London or Abu Dhabi. He said he also would not rule out the fight being held in the U.S.

Talks are ongoing for a Mayweather-Pacquiao fight, and Mayweather was in Los Angeles on Wednesday where he met with adviser Al Haymon.

Top Rank CEO Bob Arum, who promotes Pacquiao, has been publicly optimistic that a Mayweather-Pacqiuao fight on May 2 at the MGM Grand Garden in Las Vegas would become a reality. However, there hasn't been as much optimism coming from those on Mayweather's side.

Mayweather himself called into Shade 45 Radio on SiriusXM recently (WARNING: Audio is NSFW) and denied that a fight is imminent, though he did admit talks are ongoing.

"Everything that everybody's just insinuating and what everybody's been saying on TV is false," Mayweather said. "It's not true at all. Once again, I've been saying this for the longest: Pacqiuao has no say so because Pacquiao fights under Top Rank Promotions. I have Mayweather Promotions. Mayweather Promotions is my company. Pacquiao is not in a position to call any shots as of right now and he's not the 'A' side. Everything everybody has been hearing has been rumors.

"Do I want to fight Pacquiao? Absolutely. Are we negotiating? Absolutely. Has the fight been made? Not at all."

In a meeting at the Los Angeles Times office earlier this week, Pacquiao put a Jan. 31 deadline on Mayweather to come up with a decision.

He said he needed an answer so he could plan his career.

Koncz said that he'll begin more substantive talk with Khan, and another potential opponent he declined to name, next month if Mayweather hasn't responded by the end of January. Koncz said that Haymon, who advises Khan, hasn't expressed an objection to a Pacquiao-Khan bout even though Arum and Haymon don't work together.

Koncz told Yahoo Sports that even if he begins serious negotiations with Khan or another opponent after Pacquiao's deadline passes, he would not rule out a Mayweather fight if Mayweather suddenly agreed.

"Manny has said publicly that he'll wait until the end of the month and then [if there is no positive answer from Mayweather], we'll get into the real heavy negotiations with Amir or whoever else we may choose," Koncz said. "But does that mean that after Jan. 31 if Floyd does sign the contract that we wouldn't look at it or entertain it? No.

"But after Jan. 31, we're not going to sit around with our hands tied. We'll then aggressively approach our next opponent."

Stephen Espinoza, the executive vice president and general manager of Showtime Sports, conceded progress is being made in talks to finalize a deal for the long-awaited fight. However, Espinoza disputed the contention the bout is done.

"Pacquiao is still Floyd’s first choice for his May 2 opponent, and everyone on this side is working hard to make the fight happen," Espinoza told Yahoo Sports. "Talks are ongoing and we have been making progress, along with an occasional setback. Is it still alive? Very much so, but there is still a long way to go before there’s a deal in place."

It doesn't sound good for Jessie Vargas as an alternate Pacquiao opponent if Mayweather decides not to face Pacquiao. Vargas defeated Antonio Demarco on Pacquiao's undercard in Macau, China, in November and told Yahoo Sports he wanted to face the Filipino superstar next.

But Koncz all but ruled Vargas out of the running on Friday.

"I don't think Jessie Vargas is in the same league as Manny at this point in time," Koncz said. "Maybe he's an opponent down the road. But he's got no name recognition. He didn't look very impressive to me on our undercard last fight, so it would be foolish from a business sense to make that fight."