"But the rial is plummeting, the Iranian economy is in deep trouble, and it wouldn't surprise me if before the six-month mark, we see some movement from the Iranian side to try to renegotiate the deal".
The sanctions that go back into effect on Monday cover Iranian trade in automobiles and metals, including gold. Since the United States withdrawal from the Iran deal, Iran's currency has taken a nosedive, soaring up to around 120,000 rials to a dollar.
Trump's offer came after he tore up Iran's 2015 nuclear agreement in May, setting the stage for severe United States sanctions against the Islamic Republic.
Trump said this week he is willing to meet with Iran's leadership, without preconditions, "whenever they want" - a sharp departure from his threats against the regime last week.
Both Trump and Rouhani are due to address the United Nations General Assembly in NY next month.More news: China threatens new tariffs on $60 bn worth of US goods
Trump has proven very generous to United States adversaries if they meet in the context of summits, but Iran would have to swallow its pride and some humble pie too if it were to kiss the ring.
Sanctions against Iran will be strictly adhered to and act as long as the Iranian government will not change its course radically, said the US Secretary of state Mike Pompeo, reports the Associated Press.
Takht Ravanchi, who was involved in more than two years of nuclear talks with 5+1 nations, stressed that Europe's failure to neutralize the upcoming sanctions will be tantamount to "negotiations for negotiations".
So, without any direct negotiations happening, how do Iran and the USA ever get anything done?
"Iran, and its economy, is going very bad, and fast!" he said in the same missive.More news: Donald Trump defends Donald Trump Jr. Trump Tower meeting
The financial crisis in Iran could worsen to the point that mass protests make it impossible for the regime to hold on to power - though economic pressures risk galvanizing growing anti-American sentiment and support for hard-liners.
The exercise could shut down of the Strait of Hormuz, a crucial Gulf passage for shipments of numerous commodities.
Protests that began in Iran on Tuesday afternoon continued across the country in Isfahan, Shiraz, Mashhad, Karaj, Sari, Bandar Abbas, and Ahvaz. The videos could not be authenticated.
IRNA reported that all protests had taken place without official permission and were subsequently broken up by police. There were no additional details.
Mohammad Ali Jafari, commander of the Islamic Revolutionary Guard Corps (IRGC), jumped the gun and said the Iranian people would not permit any politician to sit down and talk to Trump.More news: Turkish lira skids past 5 to dollar on USA sanctions move