Philippine boxing superstar Manny Pacquiao threw down a fresh challenge to Floyd Mayweather Jnr on Thursday, daring the American world champion to "fight me" instead of setting terms that could torpedo the dream bout.

"He's all talk. Until now he has not yet agreed to fight me. Instead of blabbing, he should face me atop the ring," Pacquiao told AFP in an interview.

Ring fans the world over have been baying for a mega-fight between two of the world's greatest boxers of their generation, but previous talks have always broken down before a deal could be signed.

Pacquiao, 35, has held world titles in eight separate weight divisions.

He is training to defend his World Boxing Organization welterweight title against another undefeated American, Chris Algieri, in Macau in November.

Mayweather, who scored a lopsided victory over Marcos Maidana in a rematch in Las Vegas on Saturday, pushing his record to 47-0, later denied he was trying to safeguard his unblemished record by avoiding Pacquiao.

However, he said a Pacquiao bout would have to be on the American's terms.

Pacquiao retorted Thursday that great fighters did not duck facing the best and did not let any challenge pass by.

"I'm tired of his alibis. If he really wants to fight me, he knows how to reach me. We can fight anytime, anywhere," Pacquiao added.

The Filipino, who has won 56, lost five and drawn two fights, also dismissed the manner of Mayweather's second Maidana win, in which the American retained his World Boxing Council and World Boxing Association welterweight titles.

"To me, Maidana won that fight. Mayweather's face and lips were swelling compared to Maidana's unblemished face," Pacquiao said.

Ahead of his bout in Macau, Pacquiao said he would not underestimate Algieri, 30.

"I'm not taking Algieri lightly. He's taller than me and moves around the ring with savvy. That's why I started my training early," Pacquiao said.

His assistant trainer Buboy Fernandez said they would focus on developing a game plan, as well as honing Pacquiao's technique and footwork.

"Algieri uses the ring well and he loves to lean on the ropes. We must devise a strategy to counter this," Fernandez added, warning Pacquiao to beware of the American's left uppercut.

"He's fast, but not as fast as Timothy Bradley. So he can be an easy target for our boxer," Fernandez said.

American Bradley beat Pacquiao in a controversial split decision in 2012, but lost the rematch by unanimous decision last April.