Iran's Foreign Minister Abbas Araghchi on Tuesday said his country is "ready to engage in earnest" to seal a deal, but described "a significant wall of mistrust" between Tehran and Washington.
Mr Araghchi, writing in an opinion piece published in The Washington Post, insisted that the talks would be indirect, despite US President Donald Trump claiming the day before that they would be direct. Last month, Mr Trump expressed his desire to draw up a new deal that would put limits on Iran's nuclear programme in exchange for sanctions relief, after withdrawing the US from the original agreement – called the Joint Comprehensive Plan of Action – during his first term.
"Pursuing indirect negotiations is not a tactic or reflection of ideology but a strategic choice rooted in experience," said Mr Araghchi. "We face a significant wall of mistrust and harbour serious doubts about the sincerity of intentions, made worse by US insistence on resuming the 'maximum pressure' policy prior to any diplomatic interaction."
The US has sought to limit the possibility of Iran developing a nuclear weapon and its support for proxy groups in the Middle East through the maximum-pressure campaign of punishing sanctions that were eased under the original deal.
Mr Araghchi said that Tehran's experience of witnessing the "unwillingness or inability" of the US to fulfil commitments under the first nuclear deal has persuaded many in Iran to insist on "guarantees for mutual fulfilment of commitments".
He also criticised the double standard when it comes to developing nuclear energy and reiterated the claim that Iran's programme is meant for peaceful purposes.
"President Trump might not like the Joint Comprehensive Plan of Action ... but it contains one vital commitment: that 'Iran reaffirms that under no circumstances will Iran ever seek, develop or acquire any nuclear weapons'," he wrote. "Ten years after the JCPOA was concluded – and nearly seven years after the United States unilaterally walked away from it – there is no evidence that Iran has violated this commitment."
Mr Araghchi pointed to recent congressional testimony by intelligence chief Tulsi Gabbard, who said: "The intelligence community continues to assess that Iran is not building a nuclear weapon and supreme leader [Ayatollah Ali] Khamenei has not authorised the nuclear weapons programme he suspended in 2003."
He said that to proceed with talks, it was important to take a military response off the table. Mr Trump has said in recent weeks that "there will be bombing" and that "bad, bad things are going to happen to Iran" if it fails to reach a nuclear deal with the US.
"The proud Iranian nation, whose strength my government relies on for real deterrence, will never accept coercion and imposition," Mr Araghchi wrote. But he said: "Mark my words: Iran prefers diplomacy but it knows how to defend itself."
He said that "the ball is now in America's court". "If it seeks a genuine diplomatic resolution, we have already shown the way," he wrote. "If, instead, it seeks to impose its will through pressure, it must know this: the Iranian people respond decisively to the language of force and threat in a unified way."
The talks will take place in Oman on Saturday. The State Department confirmed that Steve Witkoff, the US special envoy to the Middle East, will be taking part.
