Pacquiao, 39, who has won world titles in an unprecedented eight weight divisions, is eyeing an April date with the Ukrainian World Boxing Organization superfeatherweight champ during a break from his duties as a Philippines senator.
“There are negotiations now about the number one pound-for-pound (boxer) which is Lomachenko,” Pacquiao said in an interview on ABS-CBN television.
“There are still talks on the weight, reducing the weight,” said Pacquiao, who has been fighting as a welterweight.
Pacquiao aides told AFP there has been no agreement on the venue and the actual date of the Lomachenko fight.
Rated by boxing experts as the world’s top “pound-for-pound” fighter, Lomachenko, 29, has lost just once in 11 pro bouts and won all the others by knockout.
Pacquiao, whose loss of his WBO welterweight title to Australia’s Jeff Horn last year left his record standing at 59 wins, seven losses and two draws, is now in the twilight of his career.
The Filipino southpaw retired briefly in 2016 but made a comeback to retake his WBO title from Jessie Vargas just months later. He has not scored a knockout win in the past eight years.
In contrast Lomachenko cemented his status last year after retaining his WBO junior lightweight title.
Lomachenko, who won gold in the 2008 and 2012 Olympics, rocketed to the top of his weight class after turning pro in 2013, winning nine world championship fights in his first 11 contests.
Pacquiao, who has not climbed the ring since the Horn loss, said last month he had opened talks to fight mixed martial arts star Conor McGregor in April.
But the Irishman said he wanted his next bout to be a return to the octagon after losing a boxing bout to unbeaten Floyd Mayweather by a 10th-round technical knockout in their much-hyped fight in Las Vegas in August last year.
On Wednesday, Pacquiao rejected calls for him to retire for good, adding he did not believe his recent losses tarnished his record.
“You know, I miss boxing,” Pacquiao said, adding he was “still okay.”
Pacquiao, elected a senator in 2016, said he would only train for three months for an April fight so he did not neglect his legislative duties.
“That’s more than enough.”
Pacquiao said Wednesday he was also open to fighting British boxer Amir Khan but said any fight would have to be done in April when the Philippine Congress would go on break.