"The Islamic Republic of Iran considers the escalation of hostile rhetoric against the Iranian nation a threat and will not tolerate its continuation without responding," General Amir Hatami said, according to the Fars news agency.

Hatami, commander of the Iranian army but not Iran's most senior officer, warned that "if the enemy makes a mistake" Iran's response would be more robust than during last June's 12-day war with Israel.

In recent days, US President Donald Trump has threatened to intervene in Iran if demonstrators were killed, while Israel's Benjamin Netanyahu has expressed support for the protests.

On December 28 merchants in Tehran staged a protest against soaring prices and the collapse of the rial, triggering a wave of similar actions in several cities, some of them deadly.

The demonstrations have yet to reach the scale of a 2022 to 2023 movement, let alone that of the mass 2009 street protests that followed disputed elections.

But the economic protests have attracted international attention, including from the leaders of the Islamic republic's international foes.

"We're watching it very closely. If they start killing people like they have in the past, I think they're going to get hit very hard by the United States," Trump told reporters on Sunday.

Netanyahu, meanwhile, told Israel's cabinet: "We stand in solidarity with the struggle of the Iranian people and with their aspirations for freedom, liberty and justice."

On Monday, the Iranian foreign ministry accused Trump and Netanyahu of inciting violence and trying to undermine Iran's national unity.

The war in June began with an unprecedented Israeli attack on Iranian military and nuclear facilities.

The United States briefly took part in the strikes, hitting three major Iranian nuclear sites.