WEDNESDAY (AFP) - Billionaire Donald Trump, who during his presidential campaign has vowed to ban Muslim immigrants and erect a wall to prevent Mexican immigration, said on Tuesday (Aug 16) that he would reject bigotry "in all forms" if elected president.

"This is my pledge to the American people: as your president I will be your greatest champion," Mr Trump said in a statement posted on Facebook.

"I will fight to ensure that every American is treated equally, protected equally, and honored equally," the Republican presidential nominee said. "We will reject bigotry and hatred and oppression in all its forms, and seek a new future built on our common culture and values as one American people."

The pronouncement comes as something of a surprise from a candidate who until now has done little to endear himself to minorities or women.

The embattled Republican presidential nominee has made a successful campaign out of incendiary rhetoric and defying political correctness.

But a recent series of gaffes had even members of his own party begging him to reel in the brash remarks.

Mr Trump's denigration of the family of a fallen Muslim American soldier was seen by many as a monumental campaign misstep.

The two sides have slung criticism at each other, with Mr Khan accusing Mr Trump of Islamophobia, assailing his "ignorance and arrogance".

The feud has become a turning point of the tumultuous 2016 White House race pitting Mr Trump against Democrat Hillary Clinton.