WASHINGTON - US President Barack Obama stood by his comparison between Iranian hardliners and his Republican opponents who he says are dead set on derailing any nuclear deal.

"What I said is absolutely true, factually," Obama said on CNN's GPS news programme that will air in full Sunday. "The truth of the matter is, inside of Iran, the people most opposed to the deal are the Revolutionary Guard, the Quds Force, hardliners who are implacably opposed to any cooperation with the international community," Obama said.

Meanwhile, Senate Majority Leader Mitch McConnell promised announced that the Senate would debate the Iran deal next month. He also lashed out at Obama on for claiming that the only option to avoid war with Iran is a deal. "That's an absurd argument, and it's the one they've made from the very beginning, that it's either what the President negotiates with the Iranians or it's war," McConnell said. "That's never been the alternative."

But Obama said the Republicans' unwillingness to consider any deal put them in league with Iranian factions opposed to the deal. "The reason that Mitch McConnell and the rest of the folks in his caucus who opposed this jumped out and opposed this before they even read it, before it was even posted, is reflective of a ideological commitment not to get a deal done," Obama said. "In that sense they do have much more in common with the hardliners who are much more satisfied with the status quo."

Replying to a question, Obama said that opponents of the Iran nuclear deal should not say he considers Iran’s Ayatollah Ali Khamenei to be a friend because there is no need to negotiate deals with friends. “You don’t negotiate deals with your friends. You negotiate them with your enemies,” Obama told CNN’s anchor Fareed Zakaria, an American journalist of Indian origin. Opponents of the deal - including Republicans, some top Democrats such as New York Senator Chuck Schumer, and Israeli Prime Minister Benjamin Netanyahu - have repeatedly argued that Iran’s supreme leader cannot be trusted. To which the Obama Administration has argued that the deal is built on “verification” through nuclear inspections, and not merely trust.

Asked what he thought of a tweet from Khameinei showing a cartoon with an apparent silhouette of Obama holding a gun to his own head. “Superpowers don’t respond to taunts,” Obama said. “Superpowers focus on what is it that we need to do in order to preserve our national security and the national security of our allies and our friends.” Obama continued, “I think that he tweeted that in response to me stating a fact, which is, is that if we were confronted with a situation in which we could not resolve this issue diplomatically, that we could militarily take out much of Iran’s military infrastructure. I don’t think that’s disputable.” But Obama, who has spent much of the last few weeks making his public case for support of the Iran deal, said he was “not interested in a Twitter back and forth with the supreme leader. What I’m interested in is the deal itself and can we enforce it.”