Pacquiao in talks over comeback but title fight 'far away'
The 45-year-old multiple world champion from the Philippines quit the sport in 2021 and made a failed tilt at his country's presidency.
He has signed up to fight a three-round exhibition bout against Japanese mixed martial artist Chihiro Suzuki next month in Saitama, north of Tokyo.
Pacquiao said he was in talks to face the American Barrios for the WBC welterweight world title but said the potential fight was still "far away".
"We're still in negotiations and we're talking about that. The fight has not materialised yet," Pacquiao, who has hinted at comebacks before, said in Tokyo.
"That negotiation is ongoing. It's going to be by December -- November or December.
"There's still a lot of things to discuss and talk about."
Pacquiao in February admitted defeat in his bid to fight at next month's Paris Olympics when the International Olympic Committee rejected a special request for him to take part.
The IOC has an age limit of 40 for Olympic boxers.
Pacquiao retired weeks after losing to Cuban Yordenis Ugas in Las Vegas in his final professional fight.
He ran for the Philippines presidency but lost the May 2022 election by a huge margin.
He returned to the ring for an exhibition in Seoul in December 2022 against a South Korean YouTuber.
He will fight Suzuki on July 28 in a 68kg boxing match of three rounds at three minutes each, with no judges' decision.
Pacquiao insisted the bout was "not an exhibition, this is a fight".
"We are looking for a knock-out for this fight," he said.
"There's going to be a lot of action in the ring and of course I'll do my best to win by knock-out."