President Obama joined other Washington lawmakers and political leaders in mourning the death of Muhammad Ali, calling the boxing great and civil rights icon a “hero” and “The greatest. Period.”

“Muhammad Ali was The Greatest. Period,” the president and first lady said in a joint statement. “Like everyone else on the planet, Michelle and I mourn his passing. But we’re also grateful to God for how fortunate we are to have known him, if just for a while; for how fortunate we all are that The Greatest chose to grace our time.”

Ali died from a respiratory illness late Friday in a Phoenix hospital. He was 74.

Obama said he kept a pair of Ali’s boxing gloves on display in his private study, just off the Oval Office, and acknowledged that Ali “wasn’t perfect.”

“For all his magic in the ring, he could be careless with his words and full of contradictions as his faith evolved,” the president said. “But his wonderful, infectious, even innocent spirit ultimately won him more fans than foes.”

Obama also called Ali's widow, Yolanda "Lonnie" Williams, to offer the first family's condolences, the White House said.  

Former President Bill Clinton and wife Hillary Clinton, the 2016 Democratic presidential front-runner, said in a joint statement that the former Olympic and professional heavyweight champion was “a blend of beauty and grace, speed and strength” that may never be matched again. 

“We watched him grow from the brash self-confidence of youth and success into a manhood full of religious and political convictions that led him to make tough choices and live with the consequences,” the Clintons also said.

Presumptive GOP presidential nominee and billionaire businessman Donald Trump tweeted: “A truly great champion and a wonderful guy. He will be missed by all!”

Kentucky GOP Rep. John Yarmuth, whose congressional district includes the city of Louisville, where Ali was born, said: "The word champion has never fit a man better. Muhammad Ali was a champion for peace, a champion for justice, and a champion for equality.”

Yarmuth recalled watching all of Ali’s championship fights and seeing him return home after defeating Sonny Liston.

“I had never seen a more perfect human being,” Yarmuth said.

Former President George W. Bush and wife Laura called Ali a “fierce fighter” and “a man of peace.”

“Muhammad Ali was an iconic and historic figure who thrilled, entertained, influenced and inspired millions,” the Bushes said. “Americans will always be proud to have been in his corner and called him one of our own.”

Democratic presidential candidate Bernie Sanders on the campaign trail called Ali "a man of great courage."

Fox News' Mike Emanuel and Chad Pergram contributed to this story.