• US concerned over Iran’s missiles, support for proxies.
• Washington has significant naval buildup in the region.
• Iran says ballistic missile programme non-negotiable.

Iran and the United States started high-stakes negotiations in Oman on Friday in efforts to overcome sharp differences over Tehran’s nuclear programme, but a dispute over widening the agenda risks derailing diplomacy and triggering another Middle East conflict.

While both sides have signalled readiness to revive diplomacy over Tehran’s long-running nuclear dispute with the West, Washington wants to expand the talks to also cover Iran’s 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 the nuclear issue in Muscat. US President Donald Trump’s son-in-law, Jared Kushner, who helped mediate in Gaza ceasefire talks, is also due to take part in the talks.

“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 hono[u]red,” Araqchi said on X on Friday.

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

In June, the US 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.

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.

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

“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,” White House Press Secretary Karoline Leavitt on Thursday told reporters.

Iran has vowed a harsh response to any military strike and has cautioned neighbouring Gulf Arab countries hosting US bases in the oil-rich region that they could be in the firing line if they were involved in an attack. Iran has one of the Middle East’s biggest stockpiles of ballistic missiles.

Missile programme red line for Tehran

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.”

In a show of defiance, Iran’s state TV said hours before the talks 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 cities”.

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 and demands the lifting of sanctions, reimposed since 2018 when Trump ditched Iran’s 2015 nuclear deal with six powers.

The United States, its European allies and Israel accuse Tehran of using its nuclear programme as a veil for efforts to try to develop the capability to produce weapons. Iran says its nuclear programme is for peaceful purposes only.

The United States government has issued an urgent travel advisory for its citizens in Iran, citing “increased security measures, road closures, disruptions to public transport, and ongoing internet blockages across the country.”

The advisory was issued by the US Virtual Embassy in Iran, urging its citizens to leave the West Asian country. In a statement on its website, the embassy urged citizens to prepare an exit plan from Iran that does not depend on US government assistance.

Those unable to leave were advised to stay in a “secure location” or other safe building. The advisory also recommended keeping a stock of food, water, and medications, and staying alert to local media for the latest updates.

The advisory came as the two countries hold talks in Oman on Friday, amid rising tensions, with the US deploying forces to the Middle East —what President Donald Trump has called a massive “armada” — while regional actors aim to prevent what many fear could escalate into a broader conflict.

The White House said that diplomacy is Trump’s first choice for dealing with Iran, and he will wait to see whether a deal can be struck at high-stakes talks, but also warned that he has military options at his disposal.

The US previously said it wanted the discussions to include Iran’s missile arsenal and other issues, while Tehran has insisted on focusing exclusively on its disputed nuclear program. It was unclear whether that disagreement had been resolved.

“The president’s diplomacy is always his first option when it comes to dealing with countries all around the world, whether it’s our allies or our adversaries,” White House press secretary Karoline Leavitt told reporters when asked about the coming talks.

‘Iran will defend itself ‘

Ahead of Omani-mediated talks, Iranian Foreign Minister Abbas Araghchi said Tehran is ready to defend itself against “excessive demands or adventurism” by the US.

The Islamic Republic will adopt the “approach of using diplomacy to secure Iran’s national interests,” Araghchi said during a meeting in Muscat with Badr al-Busaidi, Oman’s foreign minister.

Iran maintains “full readiness to defend the country’s sovereignty and national security against any excessive demands or adventurism” by the United States, Araghchi added, as US President Donald Trump refuses to rule out military action against Tehran.