Pacquiao, 35, has held world titles in eight separate weight divisions, but deals to fight 37-year-old Mayweather Jr have repeatedly broken down.
"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.
"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 defends his World Boxing Organisation welterweight title against Chris Algieri in Macau in November.