U.S. ambassador to the United Nations on ongoing war with Iran

(CBS, KYMA) - Mike Waltz, the U.S. ambassador to the United Nations, spoke with Margaret Brennan on Face the Nation Sunday about the ongoing war with Iran.

On Sunday, President Donald Trump posted to social media accusing Iran of breaking the ceasefire agreement with the U.S. by targeted vessels from France and the United Kingdom in the Strait of Hormuz.

However, President Trump said he's still offering Iran a deal, prompting Brennan to ask Ambassador Waltz if this was a presentation of terms, or if the U.S. should expect an actual, prolonged negotiation, to which the ambassador said:

"I think this will be a continuation of the terms that the vice president offered a week ago. And look, we have to take a step back here in that - President Trump, the U.S. Navy is controlling what is coming out of the straits. We've had the highest level engagement in the history of the Iranian regime, with the vice president leading. We have historic ceasefire talks going on between the Israelis and the Lebanese. The markets are up. Oil prices are relatively stable. The Iranian economy is devastated, and they've never been, I can tell you here at the United Nations, they've never been more diplomatically isolated. So Iran does not have the cards, and we are confident they will come to the table and finally give up their obsession with having a nuclear weapon."

Brennan also brought up CBS News reporting that Vice President JD Vance heading to Islamabad, Pakistan to negotiate with Iran, but Brennan said there were some back and forth Sunday morning whether Vice President Vance will be leading it or not.

This led Brennan to ask Waltz why it was important for the vice president to be there, and if it was because Iran refused to send anyone with decision making authority unless he was there, and Waltz said:

"The last 48 hours, you have their foreign minister announcing that they're going to stop attacking shipping. Then you have the IRGC saying that they will and then doing so, as President Trump pointed out, an absolute violation. So the Iranian side is in a bit of chaos. This is absolutely due to the devastating strikes on their leadership. But I think the vice president leading shows the level of engagement from the U.S. side that we are absolutely serious. And I for one, thank God for future generations that we are arresting a problem before it's too late. We're not waiting until the US has no options...and Iran has some kind of breakout, which would lead to a nuclear breakout all over the Middle East."

During the interview, Brennan brought up her colleague, Weijia Jiang, speaking to Trump Friday, who gave CBS News "an an incredibly optimistic read," with the president saying Iran had "agreed to everything, including to stop enriching uranium forever and to stop backing all proxy groups like Hezbollah. He made it sound like it's all been sorted out."

When asked if there was an agreement with certain parts of the Iranian government, but now there are others in charge, or if he was speculating about something he hopes comes true, and Waltz said:

"Anybody who has dealt with the Iranians will tell you it is often two steps forward, three steps back. They're incredibly slippery. They can't be trusted. They cheated over the years, which is one of the reasons that President Trump withdrew us from the JCPOA. They were hiding sites. They were hiding capabilities, and this is why he made the bold decision last year in Operation Midnight Hammer, to just end it once and for all. And again, we have to take the perspective that we're not waiting. We're not trusting. We are reducing their capabilities. Their military is in shambles. Their missile program is in shambles, and now, hopefully diplomatically, they will do it the easy way, rather than the hard way, of finally giving up on this illegal ambition."

Later in the interview, Brennan and Waltz talked about the president's social media post Friday saying in part, "Israel will not be bombing Lebanon any longer. They are prohibited from doing so by the USA. Enough is enough."

This led Brennan to ask how the U.S. is prohibiting Israel, an ally, from bombing in Lebanon, and what the U.S. is doing to confiscate weapons from Hezbollah, as well as how he's helping the Lebanese military do that, and Waltz said:

"First, the U.S. contributed over $250 million to the Lebanese Armed Forces. This is a tremendous historic opportunity for the Lebanese government led by President Aoun, a former general, the head of the Lebanese Armed Forces, to take their country back. Finally, with Iran on its back foot and militarily devastated, with Syria in a much better place, with the fall of the Assad regime and the effective diplomacy that we've had there, and from the pager and beeper operation to now, Hezbollah has never been in a worse place. This is a true moment, and it was a real honor for me to be at the opening of the first Israel-Lebanon talks, first ever in modern history...We have diplomacy on the march in a number of places, backed, of course, by military strength, but we have to take a moment to understand the magnitude of what's going on."

To watch more of Brennan's interview with Waltz, click here.