Trump calls Hillary Clinton a liar

US Republican presidential candidate Donald Trump said on Sunday that Democrat Hillary Clinton was a "liar" for claiming that his proposal to ban entry of all foreign Muslims into the United States has aided Islamic State's propaganda efforts.

Speaking on NBC's "Meet the Press," Trump said Clinton had no evidence to back up a charge she made during a debate on Saturday that the Republican frontrunner is becoming the extremist group's "best recruiter."

"She's a liar and everybody knows that," Trump said. "She just made this up in thin air."

Trump's call to ban all Muslims from entering the United States following a Jan. 2 attack in San Bernardino, California that killed 14 people has drawn widespread criticism from Republican rivals as well as Democrats like Clinton.

During Saturday night's Democratic debate, Clinton said Islamic State is using Trump's rhetoric to enlist fighters to radical jihad.

"They are going to people, showing videos of Donald Trump insulting Islam and Muslims in order to recruit more radical jihadists," the Democratic frontrunner said.

Counterterrorism experts and Reuters reporters who monitor Islamist online activity have found no evidence so far that Islamic State has mentioned Trump in its official online accounts.