Tehran: Iran's president on Monday blasted a US "conspiracy" against the country as vast crowds marked 40 years since the Islamic revolution at a time of heightened tensions with Washington.
"The presence of people today on the streets all over Islamic Iran... means that the enemy will never reach its evil objectives," President Hassan Rouhani told those thronging Tehran's Azadi (Freedom) square.
Chador-clad women, militia members in camouflage fatigues and ordinary citizens marched through the capital in freezing rain to mark the day in February 1979 that Ayatollah Ruhollah Khomeini ended millenia of royal rule.
Life-size replicas of Iranian-made cruise and ballistic missiles lined the route in a statement of defiance after Washington last year reimposed sanctions after pulling out of a deal on Tehran's nuclear programme.
A pre-prepared resolution was read out that proclaimed "unquestioning obedience to the supreme leader Ayatollah Ali Khamenei" and called US President Donald Trump an "idiot".
The event Monday was the culmination of official celebrations called the "10 Day Dawn" that mark the period between February 1, 1979 and February 11 when Shiite cleric Khomeini retuned from exile and ousted the shah's last government.
The state has played up this year's anniversary as 40 is symbolic of maturity in the Islamic tradition and the age at which Prophet Mohammed received revelations from God.
But despite the official festivities today's Islamic republic faces acute economic challenges as it struggles with a mix of domestic hardships and US sanctions.
State television offered blanket coverage of the commemorations, showing marchers in cities ranging from Abadan in southwestern Iran to Mashad in the northeast.
Banners held by marchers or hung along the streets bore slogans including "Death to America", "Death to Israel", "we will trample on America", "forty yeas of challenge, forty years of US defeats".
An anchor on state television warned of hostile foreign media trying to downplay the participation of Iranians in the march but expressed confidence that "they would be confounded by the unprecedented level of attendance".
Those who took to the streets were bullish despite the economic problems in the country, made worse by Washington's punitive measures.
Former public servant Saaghi insisted that it remained paramount for Iranians to stick by the revolution.
"We are here to support the revolution," the 57-year-old pensioner, who refused to give his first name, told AFP at the event in Tehran.
He compared the US sanctions and economic hardships to "riding a bicycle when someone puts a stick in the wheels" but pointed to advances in other fields as more than making up for them.
"At the revolution's 40 anniversary we are on top of scientific achievements like nanotechnology or accurate missiles," he said.
Extensive fireworks displays were held across Tehran on Sunday night.
Before the fireworks, supporters of the revolution shouted chants of "Allahu Akbar" (God is greatest) from rooftops, recalling the protests that swept Khomeini to power four decades earlier.
Current supreme leader Ayatollah Ali Khamenei is set to publish "a detailed statement explaining the 'second step' of the progress of the Islamic revolution", his official website said.