President Barack Obama paid tribute on Saturday to boxer Muhammad Ali, saying his fight for racial justice and religious tolerance "shook up the world" and was an inspiration.

"Muhammad Ali shook up the world. And the world is better for it. We are all better for it," Obama said in a lengthy statement honoring Ali's accomplishments.

The former world heavyweight boxing champion died on Friday at age 74 after suffering from Parkinson's disease for three decades.

Obama, who keeps a pair of Ali's gloves on display in his private study, said he came to know Ali as "a man who fought for us. He stood with King and Mandela; stood up when it was hard; spoke out when others wouldn't."

Obama, the nation's first African-American president, cited Ali's infamous "I am America" quote:

"'I am the part you won't recognize. But get used to me - black, confident, cocky; my name, not yours; my religion, not yours; my goals, my own. Get used to me.'"

Obama, who was golfing in Florida on Saturday, said Ali's struggle "would earn him enemies on the left and the right, make him reviled, and nearly send him to jail. But Ali stood his ground. And his victory helped us get used to the America we recognize today."

Ali "could be careless with his words" but Obama said "his wonderful, infectious, even innocent spirit ultimately won him more fans than foes," noting time Ali spent visiting sick children.

"We watched a hero light a torch, and fight his greatest fight of all on the world stage once again; a battle against the disease that ravaged his body, but couldn't take the spark from his eyes," Obama said.-Reuters