"We have a historic opportunity to strike an unprecedented agreement that addresses mutual concerns and achieves mutual interests," said Araghchi, in a post on the social media site X.

He added that a deal was "within reach, but only if diplomacy is given priority."

Tehran and Washington are due to hold a third round of nuclear negotiations on Thursday in Geneva, the latest since talks resumed earlier this month.

The talks will be held against the backdrop of heavy US military deployment in the region in recent weeks and threats by President Donald Trump of a strike if no deal was reached.

Iran has repeatedly said it would respond firmly to any attack and on Monday the foreign ministry that any strike, even limited, "would be regarded as an act of aggression".

In his post, Araghchi said Iran will "under no circumstances ever develop a nuclear weapon" but insisted on its right to "harness dividends of peaceful nuclear technology."

"We have proven that we will stop at nothing to guard our sovereignty with courage," he added.

Iran and the US held five rounds of nuclear talks last year but those negotiations were brought to an end with Israel's unprecedented attack on Iran which triggered a 12-day war.

The US joined briefly with strikes on key Iranian nuclear sites.

Iran responded at the time with drone and missile attacks on Israel, as well as by targeting the largest US military base in the Middle East, which is in Qatar.

Iran has consistently denied any ambition to build a nuclear weapon but defends enriching uranium for civilian energy and research as a sovereign right.