Amir Saeid Iravani said that Trump's reported comments "constitute a clear violation of the principles of non-interference in the internal affairs of states and enshrined in the Charter of the United Nations."

"Iran is a sovereign and independent state. It does not accept and will never allow any foreign power to interfere in its internal affairs," Iravani told reporters in New York.

"The selection of Iran's leadership will take place strictly in accordance with our constitutional procedures and solely by the will of the Iranian people, without any foreign interference," he added.

In an interview with news outlet Axios, Trump said Thursday he must be "involved in the appointment" of Iran's next leader and rejected Khamenei's son as a suitable candidate.

Meanwhile, the Iranian ambassador again described his country's retaliation to US-Israeli attacks as legal and proportionate, and said investigations were ongoing into alleged strikes on non-military sites.

"Our initial assessment indicates that some of these incidents may have resulted from the interceptions or interference by the United States defense system, which could have diverted from intended military targets."