Rep. Ryan Zinke, R-Mont., told Newsmax on Friday that the United States is making progress toward a potential agreement with Iran, though significant details still need to be resolved before any deal can be finalized.

Zinke, appearing on "National Report," said President Donald Trump has remained unwavering on the administration's core demands, including preventing Iran from obtaining nuclear weapons and ensuring freedom of navigation through the Strait of Hormuz.

"I think we're a lot closer, quite frankly," Zinke said. "You look at what our objectives [are] – and we kind of pointed them out — no nukes, no nuke material, no arsenal of destruction, and the straits are open."

While some observers have argued little has changed in recent weeks, Zinke said Iran's deteriorating position has brought the two sides nearer to an agreement.

"Their objective is just regime survival," he said. "You look at what's happening in Iran, I mean, they don't have any water. Their currency is worthless. They don't have a command structure … and you know what? The people aren't happy."

As a result, Zinke said he believes Trump is correct that negotiations with Tehran are moving in the right direction.

"The general premise of what the agreement has to be, I think the president's firm," Zinke said. "But the devil's in the details. I think we are a lot closer. We're not there yet, but we're a lot closer."

Earlier in the interview, Zinke stressed that any agreement must include a verification mechanism because neither side trusts the other.

"What happens if you don't trust?" he said. "I think the president is going into this exactly right. He doesn't trust the Iranians. They don't trust us. But there has to be some verification process, in fact, that they don't have nuclear material."

Zinke also pointed to another challenge facing negotiators: determining exactly who within Iran's leadership has the authority to negotiate and make binding decisions.

"You see that their first and second echelon of military leadership are dead," he said. "Their first echelon of political leadership is dead. And now you have a distributed command and control, primarily distributed among the military commanders, but they have a lot of autonomy."

The loss of senior Iranian leaders has complicated efforts at diplomacy, Zinke said.

"I think what we're seeing is that it's difficult to command a nation when you don't have a unified command up on top," he said. "I think that's been part of the struggle for our negotiation team — who do you talk to and what is their extent of authority?"

Although Iran's Foreign Ministry has described reports of an agreement as "speculative" and said "nothing has been finalized," Zinke said that assessment is accurate only insofar as a final document has not yet been signed.

"I think they're exactly right with 'speculative' of what the final document is going to look like on the details, and nothing is signed," he said. "They are correct. Nothing is signed. But there's a lot of work that has been done."

GET TODAY NEWSMAX+:

NEWSMAX is the fastest-growing cable news channel in America with more than 30 million people watching!

Reuters Institute reports NEWSMAX is one of the top news brands in the U.S.

You need to watch NEWSMAX today.

Get it with great shows from Rob Schmitt, Greta Van Susteren, Greg Kelly, Carl Higbie, Rob Finnerty – and many more!

Find the NEWSMAX channel on your cable system – Go Here Now

BEST OFFER:

Sign up for NEWSMAX+ and get NEWSMAX, our streaming channel NEWSMAX2 and our military channel World at War.

Find hundreds of shows, movies and specials.

Even get Jon Voight's special series and President Trump's comedy programs and much more!

Watch NEWSMAX+ on your smartphone or home TV app.

Watch NEWSMAX anytime, anywhere!

Start your FREE trial now: NewsmaxPlus.com