Issue is seen as a key stumbling block in talks with US as Washington seeks to scale back Iran’s nuclear programme

Iran is expected to resist a US proposal to transfer its stockpile of highly enriched uranium to a third country – such as Russia – as part of Washington’s effort to scale back Tehran’s civil nuclear programme and prevent it from being used to develop a nuclear weapon.

The issue, seen as one of the key stumbling blocks to a future agreement, was raised in the initial, largely indirect, talks held in Muscat, Oman, between Iran’s foreign minister, Abbas Araghchi, and Donald Trump’s special envoy Steve Witkoff.

With internal politics at their most unstable for years, the risk of escalation is rising

The letter the US president, Donald Trump, says he sent to Iran’s leadership offering to reopen talks on the country’s nuclear programme comes at a point when Iranian domestic politics is at its most unstable for years.

In the past month, the conservative-dominated parliament has asserted its power over the broadly reformist president elected last June by impeaching and sacking the experienced economy minister, Abdolnaser Hemmati, while Mohammad Javad Zarif, the vice-president and most prominent reformist, has also been forced out.