Donald Trump says President Obama poses a threat to national security because of his unwillingness to acknowledge radical Islam as a source of terrorism.

“I think he’s a threat to our country,” Trump said on Boston’s WRKO radio on Wednesday, as first reported by CNN. “I mean, he must have some kind of a thing going on because, you know, when you see that he won’t even call them by their name, attack after attack after attack.”

“It’s radical Islamic terrorism and he won’t even acknowledge it — it’s like they’re coming out of Denmark or something,” he added.

The GOP primary front-runner also said the president “doesn’t have a clue.”

The attack from Trump comes after Obama said Republicans are serving as a “potent recruitment tool” for the Islamic State in Iraq and Syria (ISIS) due to their opposition to his plan to relocate 10,000 Syrian refugees inside the U.S.

At least one assailant in the ISIS terrorist attack on Paris last week is suspected of entering the country posed as a migrant.

Trump also went after Hillary Clinton in the radio interview for similarly refusing to acknowledge radical Islam’s role in terrorism.

He said she lacks the “strength” and “stamina” to lead the country in a time of war.

“She doesn’t have the strength, she doesn’t have the stamina,” Trump said of the Democratic primary front-runner. “Hillary does not have the strength or the stamina to be president, and she doesn’t have the ideas.”