The United States and Iran held “constructive” talks on Tehran’s nuclear program on Saturday and agreed to meet again as President Donald Trump threatens military action if they fail to reach a deal.

Oman’s foreign minister acted as an intermediary in the high-stakes talks in Muscat, Iran said. The Americans had called for the meetings to be face-to-face.

However, the negotiators also spoke directly for “a few minutes,” Iran’s foreign ministry said. It said the talks were held “in a constructive and mutually respectful atmosphere.”

Disagreement over the format indicated the scale of the task facing the long-term adversaries, who are seeking a new nuclear deal after Trump pulled out of an earlier agreement during his first term in 2018.

Omani Foreign Minister Badr Albusaidi said the talks took place in a “friendly atmosphere,” adding: “We will continue to work together.”

Foreign Minister Abbas Araghchi, a seasoned diplomat and key architect of the 2015 accord, led the Iranian delegation while Trump’s special envoy Steve Witkoff, a real estate magnate, headed the US team.

“Our intention is to reach a fair and honorable agreement from an equal position,” Araghchi said earlier in a video posted by Iranian state television.

Iran’s foreign ministry spokesman Esmaeil Baqaei earlier told the broadcaster that the negotiations were “just a beginning.”

The two parties were in “separate halls” and were “conveying their views and positions to each other through the Omani foreign minister,” he posted separately on X.

Iran, weakened by Israel’s pummelling of its allies Hezbollah in Lebanon and Hamas in Gaza, is seeking relief from wide-ranging sanctions hobbling its economy.

Tehran has agreed to the meetings despite baulking at Trump’s “maximum pressure” campaign of ramping up sanctions and repeated military threats.

Meanwhile the US, hand-in-glove with Iran’s arch-enemy Israel, wants to stop Tehran from ever getting close to developing a nuclear bomb.

There were no visible signs of the high-level meeting at a luxury hotel in Muscat, where there were no flags or unusual security measures and little traffic on the streets.

Witkoff told The Wall Street Journal earlier that the US position starts with demanding that Iran completely dismantle its nuclear program — a view held by hard-liners around Trump that few expect Iran to accept.

“That doesn’t mean, by the way, that at the margin we’re not going to find other ways to find compromise between the two countries,” Witkoff told the newspaper.

“Where our red line will be, there can’t be weaponization of your nuclear capability,” he added.

The talks were revealed in a surprise announcement by Trump during a White House appearance with Israeli Prime Minister Benjamin Netanyahu on Monday.

Hours before they began, Trump told reporters aboard Air Force One: “I want Iran to be a wonderful, great, happy country. But they can’t have a nuclear weapon.”

Supreme leader Ayatollah Ali Khamenei’s adviser Ali Shamkhani said Iran was “seeking a real and fair agreement.”

Saturday’s contact between the two sides, which have not had diplomatic relations for decades, follows repeated threats of military action by both the US and Israel.

“If it requires military, we’re going to have military,” Trump said on Wednesday when asked what would happen if the talks fail.

The multi-party 2015 deal that Trump abandoned aimed to make it practically impossible for Iran to build an atomic bomb, while at the same time allowing it to pursue a civil nuclear program.

Iran, which insists its nuclear program is only for civilian purposes, stepped up its activities after Trump withdrew from the agreement.

The latest International Atomic Energy Agency said Iran had an estimated 274.8 kilograms of uranium enriched to 60 percent, nearing the weapons grade of 90 percent.

Karim Bitar, a Middle East Studies lecturer at Sciences Po university in Paris, said a deal could be a matter of the government’s very survival.

“The one and only priority is the survival of the regime, and ideally, to get some oxygen, some sanctions relief, to get their economy going again, because the regime has become quite unpopular,” he told AFP.

Mohamed Al-Araimi, ex-head of the official Oman News Agency, said the highest-level talks since the last deal crumbled indicate “a strong desire to reach a resolution.”

But he added: “Personally, I don’t believe that today’s meetings in Muscat will resolve all of these files. These matters require technical teams.”