(FOX NEWS) — Secretary of State Marco Rubio revealed what he believes to be that largest impediment to coming to an agreement with Iran in an interview with Fox News’ Trey Yingst on Monday.

Rubio referenced Iran’s “fractured” leadership and said Iranian negotiators often are in disagreement with other factions within the Iranian regime, severely limiting the scope of peace talks.

“Other than the fact that the country is run by radical Shia clerics, that’s a pretty big impediment. The other is that they’re deeply fractured internally, and I think that’s always been the case, but I think it’s far more pronounced now. The best way to understand Iran is you have a political class now. I think, look, people talk about moderates and hardliners. They’re all hardliners in Iran. But there are hardliners who understand they have to run a country and an economy, and there are hardliners that are completely motivated by theology,” Rubio said.

“The hardliners that are motivated by theology are not just the IRGC officials, but obviously the supreme leader and the council that surrounds him. And then you’ve got the political class, the foreign minister, the president, the speaker of the moguls. These guys, they’re hardliners, too, but they also understand the country has to have an economy. People have to eat, they have to figure out a way to pay salaries and their government. And so you see a tension, and you always have in that system between the Iranians who understand, let’s be hardliners. But let’s also balance that with the need to run a country and the hardliners who don’t care and have this apocalyptic vision of the future,” he continued.

Unfortunately, the hardliners with an apocalyptic vision of the future have the ultimate power in that country,” he added. “So as much as anything else, one of the impediments here is that our negotiators aren’t just negotiating with Iranians. Those Iranians then have to negotiate with other Iranians in order to figure out what they can agree to, what they can offer, what they’re willing to do, even who they’re willing to meet with.”