Each year, Iranians rally all across the country to commemorate the 1979 Islamic Revolution's anniversary.
In Tehran, hundreds of thousands marched to the Azadi (Freedom) Square on Sunday.
U.S. President Donald Trump has accused Iran of testing missiles despite Iran's commitment to not pursue its nuclear program, which the Iranian government has already dismissed.
At the rally, demonstrators chanted in support of Iran and in protest of Trump's policy. They also burned flags from Israel, Great Britain and the United States. Trump intends to break up the nuclear deal reached with Iran in 2016, in which restrictions to Iran's oil are lifted, if the U.S. Congress and the European Union don't agree to change the deal with Iran.
Iranian President Hassan Rouhani addressed the crowd in Tehran, criticizing Trump's intentions and calling for national unity.
"I request that the 40th year of the revolution, the coming year, be the year of unity. I ask principlists, reformists, moderates and all parties and all people to come and be together," said Rouhani.
The rally comes after Iran had demonstrations and riots in the first days of the year. People went out to the streets in about 80 cities and small towns in the country to protest alleged corruption, unemployment and economic conditions.
During the one-week demonstrations, about 25 people died and over 3,000 were arrested, 300 of whom remain in jail facing charges.
To Rouhani and many Iranians, these demonstrations were incited by foreign governments and were part of international intervention in the Middle East. According to him, the U.S. and Israel “wanted to create tension in the region ... they wanted to divide Iraq, Syria ... they wanted to create long-term chaos in Lebanon ... but with our help their policies failed.”
"America wanted to interfere in our state matters. But they failed because of our nation's awareness and unity," said Rouhani.
During the parade, the Iranian military put its strength on display in Azadi Square, showing the 3,750-meter range Toofan M-2 anti-tank missile and two Qadr ballistic missiles.
The Islamic Revolution was a diverse movement in Iran. Islamic, liberal and communist groups took part in it, united by their anti-imperialist stance against the Pahlavi dynasty, supported by the United States.
At the end, the Islamic faction turned out to be the most powerful and organized one, as Ayatollah Khomeini was the most popular political figure leading the movement.
"When the Revolution took place, we pushed some off the revolutionary train that we should have not," Rouhani told the crowd at Azadi Square. "Today, we have to let them board the train again."
Rouhani didn't specify who he was talking about.