Ann Coulter responded furiously to President Donald Trump after he brushed off her criticism over his declaration of national emergency in order to begin construction on the border wall.

Coulter, who is a vehement proponent of border security, called the president an "idiot" after he responded to her on Friday.

"Forget the fact that he's digging his own grave," Coulter said on a Los Angeles radio show. "The only national emergency is that our president is an idiot."

She was responding to a comment from the president earlier that she was "off the reservation."

"They have somebody," he said of the media, "Ann Coulter, I don't know her, I hardly know her, I haven't spoken to her in way over a year. But the press loves saying Ann Coulter.

"Probably if I did speak to her she'd be very nice," he continued, "I just don't have the time to speak to her. I would speak to her."

Trump remembered fondly how Coulter predicted his presidential victory at a time when she was ridiculed for it.

"So I like her," he continued, "but she's off the reservation but anybody who knows her understands that. But I haven't spoken to her, I don't follow her, I don't talk to her.

"But the press loves to bring up the name Ann Coulter," he repeated. "And you know what, I think she's fine, I think she's good, but I just don't speak to her."

Coulter has viciously attacked the president for signing the budget compromise with Democrats and then calling for a national emergency to begin construction on the wall. She believes that signing the budget compromise bill permanently undermines the president's ability to build any more wall on the border.

Later on Friday, White House press secretary Sarah Huckabee Sanders also lobbed a missive at Coulter.

"I don't think Ann Coulter has any influence over anything," Sanders told Dana Perino on Fox News. "I just don't see her as being an influential voice in this country, and certainly not one in this building."

Here's Trump brushing off Coulter's criticism: