The world champion said his bout with Jeff Horn was an opportunity to prove he could continue to be a global force.
The eight-weight world champion said the bout with the undefeated Horn was an opportunity to prove he could continue to be a global force at the age of 38 as he juggles boxing with a full-time job in politics.
"(I want) to defend my crown and prove that I'm still there in boxing, despite of my ambitions in office as a senator," he told reporters on an Australian visit to promote the July 2 bout.
"I'm still handling my boxing career. I'm still there. I'm not done yet in boxing."
Pacquiao first won a world title at flyweight (112lb) two weeks before his 20th birthday in December 1998 to start a storied career that has seen him win global belts all the way up to super welterweight (154lb).
"Boxing is my passion. I started when I was young - it's part of my life," said Pacquiao.
"It depends on how you discipline yourself, how you train and prepare yourself. It's a matter of discipline."
"Pac-Man", who briefly retired early last year before making a successful comeback against Jessie Vargas in Las Vegas in November, added that he was excited to face Horn, 29, in the WBO welterweight title fight at the 55,000-capacity Suncorp Stadium.
"I'm not going to predict the fight but I will do my best to entertain the fans," he said.
"I'm very excited to fight here, I've fought a lot of fighters in the (United) States. This is new, I'm excited. I can't wait for the fight."
Pacquiao (59-6-2, 38 knockouts) is an overwhelming favourite against Horn (16-0-1, 11 knockouts), but the Filipino great has not stopped an opponent since his 12th round TKO of Miguel Cotto in 2009.
"I don't know much about him (Horn) but I know he's a fighter. I haven't watched his fights yet but I'm going to get his last three fights and watch them," he said.