Dick Cheney on Fox News. Fox News Former Vice President Dick Cheney passionately denounced the Iran nuclear deal in a Fox News interview with Sean Hannity on Tuesday night.

After Hannity asked Cheney why President Barack Obama wants the agreement, the former vice president bluntly said that he didn't know.

"You asked the key question, Sean. And that is: What the hell is the president thinking of when he thinks this is a great deal? And I frankly simply do not understand. I haven't met anyone who can explain it to me," he said.

President Barack Obama announced Tuesday morning that the US and other powers had struck a deal with Iran to curb its ability to produce a nuclear weapon. In exchange, Iran earned a number of concessions, including the rollback of economic sanctions.

But Cheney, like many Republican foreign-policy hawks, has a litany of concerns about the agreement, which he said would only lead to Iran getting a nuclear bomb if implemented. Cheney predicted that other countries would then arm themselves with nuclear weapons in response.

"I can't help but just shake my head," Cheney said of Obama. "The one thing that really disturbed me was when he said we have quote 'stopped the proliferation of nuclear weapons.' That's a lie. The fact of the matter is the situation we've got, when Iran ends up with a nuclear weapon, that is bound to lead to others in the region to protect themselves."

Cheney had a dire warning about what would happen after other countries build up their nuclear arsenals.

"That will in fact I think put us closer to the actual use of nuclear weapons than we've been at any time since Hiroshima and Nagasaki in World War II," he said.

Watch the full interview below: