Iran's supreme leader Ayatollah Ali Khamenei said Saturday that a landmark nuclear deal with world powers would not affect the country's avowed stance against an "arrogant" United States government.
The remarks were greeted by chants of "Death to America" from the crowd at a ceremony in Tehran to mark the end of the Muslim fasting month of Ramadan.
While such hardline rhetoric is familiar - the US and Iran severed diplomatic ties the year after the Islamic revolution of 1979 - the supreme leader's words highlighted the sharp differences between Iran and the West over the multiple conflicts gripping the Middle East despite Tuesday's historic nuclear deal.
"Our policies toward the arrogant US government will not change. US policies in the region differ from Iran's by 180 degrees," he said.
The deal between Iran and six powers led by the United States has raised suggestions it might pave the way for greater co-operation from Tehran on other issues, particularly the war against the Islamic State group in Iraq and Syria.
Khamenei did not rule out that possibility, noting there can be "exceptional circumstances" that justify talks, such as the nuclear issue, but insisted there would be no broader detente.
"We haven't any other talks with the US on regional and bilateral issues," he said.
Tehran and Washington had informal discussions in 2001 when US troops invaded Afghanistan to oust the Taliban from power after the September 11 attacks.
Khamenei, who has the final say on all matters of state, has said repeatedly that Iran's engagement with the powers was solely to reach a nuclear deal that was in its national interest.
He told worshippers that the agreement would not alter Iran's support for the governments of Syria and Iraq nor its backing of "oppressed people" in Yemen and Bahrain, and the Palestinians.
The US, in contrast, he said, had backed Israeli "atrocities" in Gaza last year.
"How can we negotiate and agree with such policies?" Khamenei asked.
Iran has provided money and military advisers to support President Bashar al-Assad's regime in Syria against rebels it accuses Gulf Arab states of arming with Western connivance.
It has also strongly opposed Saudi-led military interventions against fellow Shiites in Bahrain and Yemen.
Riyadh, the region's main Sunni power, has in turn accused its Shiite rival Iran of malign military intent and meddling.
The days since the accord was struck on Tuesday have seen the United States and Britain seek to reassure both Gulf Arab states and Iran's arch-foe Israel about their security.
Israel, the Middle East's sole if undeclared nuclear power, was the biggest opponent of the West's diplomacy with Iran, with Prime Minister Benjamin Netanyahu lobbying US lawmakers to block it.
US President Barack Obama on Wednesday hit back at the deal's critics, saying they were at odds with "99 per cent" of the world and had failed to offer any real alternative.
But he was also at pains to reassure Saudi Arabia, whose Foreign Minister Adel al-Jubeir held talks in Washington.
The White House said on Friday that Jubeir had welcomed the accord. The Saudi embassy in Washington said he had "reaffirmed Saudi Arabia's support for an agreement that prevents Iran from obtaining a nuclear capability." Within a few months, the deal stands to give Iran relief from UN and Western sanctions that have ravaged its economy.
In return, Iran has pledged to place curbs on its nuclear programme for at least a decade to allay Western concerns about its ambitions.
Iran has always denied seeking a nuclear weapon, a position Khamenei restated on Saturday.
He recalled that he himself had issued a religious edict or fatwa saying that the atomic bomb was against the Quran.
He stressed that the agreement with Britain, China, France, Russia and the United States plus Germany was not yet law and would have to be carefully scrutinised.
But he praised President Hassan Rouhani and Iran's negotiators.
"They really took pains and worked hard," Khamenei said of the team led by Foreign Minister Mohammad Javad Zarif, who said before the deal that it could be followed by greater co-operation against IS.
"The text that has been prepared, whether it is approved or not, they have done their part and they should have their reward," Khamenei added.
Under a law passed last month, Iran's parliament must approve the nuclear deal but questions about whether the West honours its side of the bargain rest with the country's Supreme National Security Council, rather than lawmakers.