He said President Donald Trump is intent on getting Iran to "behave like a normal country".
In an interview with PANA news agency, Bahram Qassemi voiced Iran's readiness to hold negotiations with Saudi Arabia, saying Tehran has not rejected calls for mediation by third countries.
Protests broke out on Sunday for a sixth night in Iranian cities, including Kazeroon in the south.
The protests have often begun with slogans against the high cost of living and alleged financial corruption but quickly turned into anti-government rallies.
"This is just about Iranians' dissatisfaction with their own government, and the President is pretty clear, we want the Iranian people to have a strong voice in who their leadership will be", Pompeo said.
As part of the withdrawal, the USA will on Monday begin to sanction Iranian transactions with US dollar banknotes; trade in gold and precious metals; direct or indirect sales of graphite, raw or semi-finished metals; and Iran's automotive sector.
In May, the USA pulled out of the 2015 deal between world powers and Tehran under which worldwide sanctions were lifted in return for curbs on its nuclear programme.
Washington has told countries they must halt all imports of Iranian oil from 4 November or face U.S. financial measures.
"They're the world's largest state sponsor of terror", Secretary of State Mike Pompeo told Indonesian television in an interview Sunday.
President Donald Trump's withdrawal from the landmark agreement, signed by the U.S. and five other world powers, remains one of the most consequential foreign policy decisions of his presidency.
Sanctions on Iran's oil industry and central bank are set to be restored on November 4.
"We're happy to talk, if there's an arrangement that is appropriate, that can lead to a good outcome", Pompeo said.
Trump administration officials say the sanctions are being restored starting Monday in an effort to change the Iranian regime's behavior.
Remaining sanctions - including on Iran's oil and gas sector and central bank - will resume on Nov 5.
United Nations inspectors said Iran was complying with the deal, but Trump argued that it didn't do enough to curb Iran's malign activity in the region.
She said the collapse in the value of the rial was not driven by purely economic factors but instead by people rushing to buy gold or hard currency as a safe haven for their savings because they do not trust the government to improve the situation.