Manila (AFP) - Manny Pacquiao threw down the gauntlet to Conor McGregor - and took a dig at Floyd Mayweather - as he promised to give the mixed martial arts (MMA) star a "real boxing match".

McGregor lost a megabucks fight in August against the unbeaten Mayweather, who defeated Pacquiao in their disappointing 'Fight of the Century' in 2015.

"Happy Thanksgiving! Stay fit my friend. #realboxingmatch #2018 @thenotoriousmma," Pacquiao posted on Twitter and Instagram, using McGregor's social media handle.

There was no immediate reaction from McGregor on social media, and Pacquiao's media team told AFP on Friday (Nov 24) that there were "no negotiations yet" about a McGregor match.

Pacquiao, who turns 39 in three weeks, lost his World Boxing Organisation welterweight title to Australian former schoolteacher Jeff Horn in July, having come out of retirement in 2016 to take the belt from American Jessie Vargas.

McGregor has not fought in MMA or boxing since losing to Mayweather by 10th-round technical knockout in their much-hyped bout in Las Vegas.

Pacquiao's "#realboxingmatch" reference appears to be a swipe at Mayweather, who beat the Filipino by unanimous decision in 2015 in the richest fight in boxing history.

The Filipino, who fought with a shoulder injury that later required surgery, has insisted he beat the American, saying he "didn't do nothing, he was always moving outside".

Mayweather retired with a record of 50-0 after the McGregor bout.