TEHRAN - Iran has accused the United States of "inciting" anti-government protests that have gripped the country, and said the Donald Trump administration had "flouted" international law and the principles of the UN charter by supporting the unrest in a series of "absurd tweets".

In a letter sent to Antonio Guterres, the UN secretary general, on Wednesday, Gholamali Khoshroo, the Iranian ambassador to the UN, said the U.S. had "crossed every limit" by "inciting Iranians to engage in disruptive acts".

"[The U.S.] has stepped up its acts of intervention in a grotesque way in Iran's internal affairs under the pretext of providing support for sporadic protests, which in several instances were hijacked by infiltrators," Press TV quoted Khoshroo as saying.

He criticized Trump and Vice President Mike Pence directly for their "numerous absurd tweets", that called on Iranians to "change their government".

"The U.S. Department of State went so far as admitting that the U.S. government wants to encourage protesters in Iran to change their government, admitting that the U.S. is engaged in interfering with the internal affairs of Iran through Facebook and Twitter," Khoshroo said.