Changes requested by Iran's Foreign Minister Abbas Araghchi prompted the cancellation on Monday of his participation in a nuclear policy conference in Washington.
Shortly before Mr Araghchi's scheduled online appearance at the event, a representative for the Carnegie Endowment for International Peace told those in attendance that at the last minute, the Iranian team had asked to cut back the question-and-answer portion.

“Unfortunately, the Foreign Minister’s team subsequently requested changes to the previously agreed format, which would have severely curtailed the ability of the moderator and the audience to question the Foreign Minister,” the Carnegie International Policy Conference said in an email elaborating on the decision.
“As a result, Carnegie made the decision not to proceed with the session.”
In a statement to The National, Iran’s mission to the UN accused the Carnegie Endowment of trying to “alter the format of the keynote into a debate”.
In prepared remarks seen by The National, Mr Araghchi was to have said that Iran’s peaceful nuclear programme has been "mischaracterised and misunderstood due to wrong perceptions and politically motivated narratives".
"Such narratives have shaped misguided policies and hindered opportunities for meaningful diplomacy," he was to say in the undelivered speech. "I am cautiously optimistic that this toxic dynamic may be about to change."
He suggests that US President Donald Trump recognise past policy failures in the Middle East, which he said had cost American taxpayers "trillions of dollars ... with zero gains for the United States".
Iran has long been willing to engage with Washington on the basis of "mutual respect and equal standing", he says, including recognition of its rights as a signatory to the Nuclear Non-Proliferation Treaty to produce nuclear fuel for power plants.
Iran agreed to what he calls "the most intrusive inspection regime the world has ever seen" under the 2015 nuclear deal. "We have made abundantly clear that we have nothing to hide" he adds.
Mr Araghchi says that whatever agreement may be concluded should be pillared on guaranteeing Iran’s economic benefits coupled with robust monitoring and verification, ensuring the peaceful nature of Iran’s nuclear programme.
“The scope of negotiations must also be clear; negotiations should remain focused solely on removal of sanctions and the nuclear issue,” he says. “In a region as rough and volatile as ours, Iran will never put its security up for negotiation.”
Mr Araghchi was not on the original list of speakers for 2025 Carnegie International Nuclear Policy Conference, but was added on Saturday.
In place of Mr Aragchi, Carnegie bumped up a panel discussion about nuclear policy, Ukraine and Russia.
Several hours after the Iranian Foreign Minister was to speak at the event, he attempted to explain the entire ordeal on X in a lengthy post.
"I am accustomed to tough questions from journalists and ordinary concerned citizens alike. But turning my keynote address into an open Q&A would either turn the event into a public negotiation, which I am not willing to countenance, or be unsatisfactory for an audience probably looking for details on where the talks might go," he wrote.
"I regret that my intended host was neither cognizant nor considerate of these sensitive dynamics."
Mr Araghchi's appearance at the Washington event would have come as talks between Iran and the US on Tehran's nuclear programme gain momentum following a series of meetings in Rome.
For years, Washington and Tehran have been at odds over Iran's nuclear activities. The US fears Iran is working towards building a nuclear weapon, but Tehran claims its programme is for peaceful purposes.

The second round of negotiations led by Mr Araghchi and US envoy to the Middle East Steve Witkoff ended on a positive note in the Italian capital.
The Oman-brokered talks lasted for four hours and officials declared it a “good meeting” that yielded progress.
On Sunday, Omani Foreign Minister Badr Al Busaidi thanked Mr Araghchi and Mr Witkoff “for their highly constructive approach” to the discussions.
“These talks are gaining momentum and now even the unlikely is possible,” Mr Al Busaidi said on X.