Iran and the United States are set to hold high-stakes negotiations in Oman on Friday over Tehran’s nuclear programme, but a dispute over the agenda, most notably differences over Tehran’s formidable missile programme, suggests progress will be hard-won, with the threat of another Middle East war looming.

While both sides have signalled readiness to revive diplomacy over Tehran’s long-running nuclear dispute with the West, Washington wants the talks to cover Iran’s nuclear programme, its ballistic missiles, support for armed groups around the region and “treatment of their own people”, US Secretary of State Marco Rubio said on Wednesday.

Iran has said it wants Foreign Minister Abbas Araqchi and US Middle East envoy Steve Witkoff to discuss only nuclear issues in Muscat.

“Iran enters diplomacy with open eyes and a steady memory of the past year. We engage in good faith and stand firm on our rights. Commitments need to be honoured,” Araqchi said on X on Friday ahead of the talks.

“Commitments need to be honoured. Equal standing, mutual respect and mutual interest are not rhetoric — they are a must and the pillars of a durable agreement.”

In June, the United States struck Iranian nuclear targets, joining in the final stages of a 12-day Israeli bombing campaign. Tehran has since said its uranium enrichment work has stopped.

Tehran’s leadership remains deeply concerned that US President Donald Trump may still carry out his threats to strike Iran amid a buildup by the US Navy near Iran.

The US naval buildup, which Trump has called a massive “armada”, has followed a bloody government crackdown on nationwide protests in Iran last month, heightening tensions between Washington and Tehran.

White House Press Secretary Karoline Leavitt on Thursday told reporters that Trump was looking to determine whether a deal can be struck but also issued a warning.

“While these negotiations are taking place, I would remind the Iranian regime that the president has many options at his disposal, aside from diplomacy as the commander-in-chief of the most powerful military in the history of the world,” she added.

Trump has warned that “bad things” would probably happen if a deal could not be reached, ratcheting up pressure on the Islamic Republic in a standoff that has led to mutual threats of airstrikes.

Iran has warned it would respond harshly to any military strike and has cautioned neighbouring countries hosting US bases that they could be in the firing line if they were involved in an attack.

“It’s very difficult to see them conceding enough in talks tomorrow for the US credibly to be able to claim that it’s made a breakthrough. And this, is where I think military conflict is more likely than not,” Edmund Fitton-Brown, senior fellow at Washington-based think-tank FDD, said.

Uranium enrichment

Negotiators in Oman will have to navigate Iran’s red line on discussing its missile programme to reach a deal and avert future military action. Tehran has flatly ruled out talks on its “defence capabilities, including missiles and their range.”

Hours before the talks, Iran’s state TV said that “one of the country’s most advanced long-range ballistic missiles, the Khorramshahr 4”, had been deployed at one of the Revolutionary Guards’ vast underground missile complexes.

However, Tehran is willing to show “flexibility on uranium enrichment, including handing over 400 kg of highly enriched uranium (HEU) and accepting zero enrichment under a consortium arrangement as a solution,” Iranian officials told Reuters last week. Iran also insists that its right to enrich uranium is not negotiable.

Iran says its nuclear activities are meant for peaceful, not military purposes, while the US and Israel have accused it of past efforts to develop nuclear weapons.

Tehran’s influence throughout the region has been severely weakened by Israel’s attacks on its regional allies - known as the “Axis of Resistance” – from Hamas in Gaza to Hezbollah in Lebanon, the Houthis in Yemen and militias in Iraq – as well as by the ousting of Iran’s close ally, Syrian dictator Bashar al-Assad.