"That is why we've offered this window since May 8, as sort of a drawdown period" ahead of the November 4 deadline, the official said.
This time the situation may be different if U.S. officials' briefings are anything to go by.
The country also banned imports on 1,300 products, including appliances, textiles, and healthcare in a move to resist USA sanctions.
After US president Donald Trump chose to withdraw from world powers' deal with Iran on its nuclear program, some US sanctions are to be reimposed in August and some in November. The rial sank as low as 90,000 against the dollar in the unofficial market on Monday from 87,000 on Sunday and around 75,500 last Thursday, according to a Reuters report. At the end of 2017, it stood at 42,890.
Similar economic protests roiled Iran and spread to some 75 cities and towns at the end of previous year, becoming the largest demonstrations in the country since the months-long rallies following the 2009 disputed presidential election.
Tehran's prosecutor Abbas Jafari-Dolatabadi said some protesters near the bazaar were arrested on Monday and would not be released before going to trial. This is doubly true because remaining signatories are trying to save the Iran deal.
"We are all angry with the economic situation".
"In the coming months we will see much more intervention in the economy by the government, a centrally imposed style of management by diktat", he said.
Whether or not they continue, it is worthwhile noting that at least some of the protesters are taking issue with Iranian attempts to wield influence throughout the Middle East rather than focus on domestic issues. The deal was the centerpiece of Rouhani's plans to open Iran's economy, which won him two landslide elections but has yet to bring widespread economic benefits for many Iranians.
These latest protests have hit Iranian commercial areas, including the sprawling, historic warrens of Tehran's Grand Bazaar, the home of conservative merchants who backed the country's 1979 Islamic Revolution and overthrow of Shah Mohammad Reza Pahlavi.
On a closer look, this same warning by the US Department has been given to the European world too. The ensuing turmoil has seen worldwide firms and oil companies back away from their own billion-dollar deals with Iran.
It remains unclear who is leading the protests, but analysts say hardliners wanting to challenge Mr Rouhani most likely sparked similar demonstrations last December and into January. "Iran likes to meddle".
He predicted Iran might ultimately enter a fresh recession as lower oil revenues prompted the government to put public sector projects on hold and as the economy became more militarized in response to US pressure.
If Trump's decision to pull out of the nuclear agreement achieves nothing else, it has already had a modicum of success in giving support to dissidents in Iranian eyes.
Widespread protests also erupted at the end of previous year across Iran over the ongoing economic situation.