We take a look back at some of Floyd "Money" Mayweather's best moments in front of the microphone. (1:24)

Floyd Mayweather Jr. is continuing to taunt Conor McGregor, saying he would put boxing gloves on again only to fight the UFC lightweight champion -- though that doesn't move the bout any closer to happening.

During a public appearance Friday in Liverpool, England, Mayweather urged McGregor to face him in June.

"For Conor McGregor, I'm coming out of retirement -- just to fight Conor McGregor," said Mayweather, after he instructed the audience to videotape him with their phones.

"I don't want to hear no more excuses about the money [or] about the UFC. Sign the paper with the UFC, so you can fight me in June. Simple and plain. Let's fight in June."

The proposed fight has made constant headlines during the past year but has failed to come together thus far.

Mayweather's comments were more or less in line with what he has said throughout a series of public appearance on his "Undefeated" tour. The McGregor fight has become a constant topic for him to address.

Earlier this week, Mayweather told ESPN, "I don't know if it's going to happen. If Conor McGregor really wants the fight to happen, stop blowing smoke up everybody's ass and sign the paper."

McGregor, 28, has demanded a guaranteed $100 million payday to face Mayweather. He is also under exclusive contract with UFC, which presents a unique hurdle in making the fight.

One constant in the running drama surrounding the potential fight has been Mayweather's assertion that he is the primary draw of the two, which he reiterated Friday.

"When I faced Arturo Gatti [in 2005], I went to his turf," Mayweather, 40, said. "He was the 'A' side, I was the 'B' side. I didn't cry. I didn't complain. When I fought Oscar De La Hoya [in 2007], he was the 'A' side. I was the 'B' side. I didn't cry, and I didn't complain. I beat him, and I became the 'A' side."

McGregor hasn't fought since he won the UFC lightweight title by knocking out Eddie Alvarez in November. He is currently taking a break as he expects the birth of his first child in May.

Mayweather, who boasts a professional record of 49-0, hasn't fought since he retired in late 2015.

UFC president Dana White, who publicly offered Mayweather and McGregor $25 million for the fight at one point, has expressed doubt in it ever happening.