Iran's president on Monday insisted "enemy" plots against the country would fail as vast crowds marked 40 years since the Islamic revolution at a time of heightened tensions with the United States.
"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, decrying a "conspiracy" involving Washington.
Chador-clad women, militia members in camouflage fatigues and ordinary citizens marched through the capital in freezing rain to commemorate the day in February 1979 that Ayatollah Ruhollah Khomeini ended millenia of royal rule.
The routes leading up to the square were packed with people as loudspeakers blared revolutionary anthems and slogans.
Life-size replicas of Iranian-made cruise and ballistic missiles stood in a statement of defiance after the US last year reimposed sanctions following its withdrawal from a deal on Tehran's nuclear programme.
Rouhani lambasted calls from Washington and Europe for a fresh agreement to curb Iran's missile programme.
"We have not, and will not request permission from anyone for increasing our defensive power and for building all kinds of... missiles," he told the crowd.
Speaking from a flower-festooned stage overlooking the square the president warned that Iran was now far stronger than when it faced off against Saddam Hussein's Iraq in a devastating conflict from 1980-88.
"Today the whole world should know that the Islamic Republic of Iran is considerably more powerful than the days of the war," Rouhani said.
A pre-prepared resolution was read out ahead of his speech that proclaimed "unquestioning obedience to the supreme leader Ayatollah Ali Khamenei" and called US President Donald Trump an "idiot".
The events Monday were 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.
'Support the revolution'
State television offered blanket coverage of the commemorations, showing marches 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".
A number of Israeli and American flags were set on fire by the crowds.
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.
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