WASHINGTON -- US President Donald Trump said on Friday that the United States would "get involved" if Iranian authorities "start killing people" during the country's current unrest, but would not deploy ground troops.

"If they start killing people... we will get involved," Trump told reporters on the situation in Iran.

"That doesn't mean boots on the ground, but it means hitting them very, very hard where it hurts," he added.

Trump and other senior US officials have repeatedly warned that Washington would take action if Iran "kills peaceful protesters."

Iran's Foreign Ministry on Wednesday condemned what it described as "interventionist and deceptive" remarks by the Trump administration about the unrest, saying they reflected Washington's continued hostility toward the Iranian people.

Protests have erupted in several Iranian cities since late December over the sharp fall of the rial and long-standing economic hardship. Iranian authorities have acknowledged the demonstrations and voiced willingness to address economic grievances, while warning against violence and vandalism.

Dozens of people, including protesters and members of the security forces, have been killed since the protests began, according to various reports. There is no official figure for the death toll.