Boxing legend Muhammad Ali has criticised US Republican presidential hopeful Donald Trump's proposal to ban Muslims from entering America.

Without naming Trump, Ali said that Muslims "have to stand up to those who use Islam to advance their own personal agenda".

The three-time world heavyweight champion, 73, is a cultural icon and one of the world's most famous Muslims.

Trump says he will never leave the race, despite widespread criticism.

The White House had said that his comments about Muslims "disqualified" him from running for the presidency.

'Ruthless violence'

Ali's statement was directed at "presidential candidates proposing to ban Muslim immigration to the United States".

"They have alienated many from learning about Islam," he said.

The former heavyweight champion also strongly criticised violence committed by jihadists from the Islamic State (IS) group.

"True Muslims know that the ruthless violence of so called Islamic Jihadists goes against the very tenets of our religion," he said.

"These misguided murderers have perverted people's views on what Islam really is."

Donald Trump received an award named after the former heavyweight champion in Arizona in 2007. Photo: AP

Facebook creator and CEO Mark Zuckerberg also expressed solidarity with Muslims in a Facebook post on Wednesday.

"After the Paris attacks and hate this week, I can only imagine the fear Muslims feel that they will be persecuted for the actions of others," he wrote.

"As a Jew, my parents taught me that we must stand up against attacks on all communities. If you're a Muslim in this community, as the leader of Facebook I want you to know that you are always welcome here and that we will fight to protect your rights."

Ali in his statement said there was there was "nothing Islamic about killing innocent people in Paris, San Bernardino, or anywhere else in the world".

The former boxer was diagnosed with Parkinson's disease in 1984, after quitting the sport. Born by the name of Cassius Clay, he converted to Islam and changed his name in 1964.

His statement comes after President Barack Obama's televised address to the nation on Sunday night, in which he called on Americans to turn away from discrimination.

"Muslim Americans are our friends and our neighbours, our co-workers, our sports heroes," Obama said.

Trump reacted to Obama's statement saying: "Obama said in his speech that Muslims are our sports heroes. What sport is he talking about, and who?"

The presidential candidate has met Ali several times, and even received an award named after the former heavyweight champion in 2007.

Trump's comments about Muslims came after the deadly shootings in San Bernardino, California.

He called for "a total and complete shutdown of Muslims entering the United States until our country's representatives can figure out what is going on".

A Muslim couple, believed to have been radicalised, killed 14 people at a health centre and left scores injured.

Trump is the current frontrunner among the Republicans running for president, six weeks before the primary contests begin for each party to pick their nominee.

He also alluded to running as an independent in a tweet linking to a USA Today poll which found 68% of his supporters would vote for him if he left the Republican party.