The United States has issued a fresh security warning for its citizens in Iran, urging them to leave the country immediately as diplomatic tensions between Washington and Tehran escalate ahead of planned talks in Oman.

In an alert released early Friday, the US Virtual Embassy in Iran advised American nationals to arrange departures without relying on US government assistance, underscoring growing concerns about the security situation on the ground.

The warning comes hours before US and Iranian officials are due to hold talks in Muscat, though expectations for progress remain low amid unresolved disagreements over the meeting’s scope and agenda.

US Special Envoy Steve Witkoff and Jared Kushner, US President Donald Trump’s son-in-law, are expected to represent Washington, while Iran’s delegation will be led by Foreign Minister Abbas Araghchi, according to officials on both sides.

If held as planned, the meeting would mark the first formal engagement between the two countries since tensions surged last June, when a brief but intense conflict with Israel prompted US airstrikes that damaged Iran’s key nuclear facilities.

However, lingering disputes over the venue and substance of the talks have raised doubts about their outcome, with the possibility of US military action still looming.

Washington has reportedly pressed Tehran to dismantle its stockpile of enriched uranium, curb its ballistic missile program, and halt support for armed groups across the Middle East. US President Trump has repeatedly warned that failure to meet US demands could trigger military strikes.

Iran has rejected the conditions, calling them a violation of its sovereignty, and has warned it would retaliate against any attack by targeting US forces in the region as well as Israel.

The diplomatic push unfolds against a backdrop of heightened regional tension, with the US significantly reinforcing its military presence in the Gulf. Trump has described the deployment led by the aircraft carrier Abraham Lincoln as a “massive armada” sent ahead of the talks.

The negotiations were initially planned for Istanbul, with Turkey playing a mediating role and several regional foreign ministers expected to attend. 

Tensions have also been fuelled by domestic unrest in Iran following nationwide protests earlier this year. Human rights groups say security forces responded with lethal force, killing thousands of demonstrators.

While Trump had earlier threatened to intervene in support of protesters, the US ultimately refrained from taking direct military action, opting instead for diplomatic engagement amid growing international scrutiny.