Iran's president accused his US counterpart Donald Trump on Monday of seeking to bring the Islamic republic "to its knees" as the country marked the 1979 revolution that toppled the shah.

The revolution removed a pro-US government in Iran, and the subsequent hostage-taking of American diplomats in Tehran ushered in decades of hostility between the United States and Iran.

This year's celebrations carry additional weight following Trump's return to the White House. During his first term, Trump pursued a policy of "maximum pressure" against the Islamic republic.

In the morning, people gathered in public spaces across Iran, accompanied by pop songs and patriotic ballads, to celebrate the anniversary of the overthrow of Shah Mohammad Reza Pahlavi.

In Tehran, they headed to the symbolic Azadi tower, whose name means "freedom" in Persian, and which is in a square formerly named in honour of the shah.

"Trump says, 'we want to talk', and... (then) he signs in a memorandum all the conspiracies to bring our revolution to its knees," Pezeshkian told the crowd, referring to Trump's reinstatement of sanctions against Tehran earlier this month.

"We are not looking for war," he said while adding that Iran "will never bow to foreigners".

Chanting anti-American and anti-Israeli slogans, crowds formed Monday in the streets of Shiraz and Bandar Abbas in the south, Rasht in the north, Kermanshah and Sanandaj in the west, and the holy city of Mashhad in the east, according to images broadcast on television.

Attendees, many of them families, carried portraits of supreme leader Ayatollah Ali Khamenei and the green, red and white flag of Iran, as well as the banners of Tehran-backed groups such as Hezbollah.

Iranian-made missile replicas and military equipment were on display, drawing crowds of families.

You can't trust America!

Children, draped in Iran's flag, clambered over an air defence system, and some people carried portraits of Khamenei.

"Negotiating with the United States is pointless because they lie," said Parvaneh Samakhani, a 52-year-old teacher.

During his first term, which ended in 2021, Trump had pursued a policy of "maximum pressure" against Iran, an approach he has restored since returning to office.

Trump pulled Washington out of the 2015 nuclear deal, undermining an agreement that had given Iran sanctions relief in exchange for curbs on its atomic programme.

As he signed the order instructing US departments to design new sanctions against Iran on February 4, Trump voiced optimism for a "deal with Iran and everybody can live together".

The US president also warned that if he were assassinated by Iran, the country would be "obliterated".

"Iran made many concessions, but then Trump came and tore up the deal," said Samakhani, dressed in a black chador.

"You can't trust America!" she said, as some waved caricatures of Trump and Israeli Prime Minister Benjamin Netanyahu.

With Trump's return to office, "history is repeating itself," said Mehdi Sajadfar, a 24-year-old shopkeeper.

"Everything is a lie" when it comes to the United States, he added, as demonstrators chanted "Death to America".

In his speech, Pezeshkian said the United States sought to weaken Iran by sowing "division".

"If we join hands, we are capable of resolving all the country's problems," said the Iranian president.

Iran's 10-day celebrations marking the ouster of the shah start each year on January 31, the anniversary of the return to Tehran of Ayatollah Ruhollah Khomeini in 1979 from exile.

Iranian officials had urged citizens to attend the festivities in large numbers after Trump's sanctions announcement.

AFP