Donald Trump is a disgrace and should pull out of the United States presidential race, Saudi Arabian billionaire Prince Alwaleed bin Talal tweeted late on Friday.

"@realDonaldTrump You are a disgrace not only to the GOP but to all America," Alwaleed said on his official Twitter account, @Alwaleed_Talal.

"Withdraw from the U.S presidential race as you will never win."

Alwaleed is an unusually outspoken member of the Saudi royal family, who chairs Kingdom Holding Co.

The diversified firm's interests include US-banking giant Citigroup.

A statement early Saturday from Alwaleed's office said his tweet was in response to Trump's "anti-Islam statement".

Alwaleed is a devout but moderate Muslim.

Trump, the frontrunner for the Republican nomination, has been lambasted both in the US and abroad for his proposal made on Monday to temporarily bar Muslims from entering the US.

Trump's comments followed a shooting rampage by a Muslim couple in San Bernardino, California, which left 14 dead.
Source: AFP