China, the top buyer of Iranian oil, and Iran's neighbor Turkey, are resolutely opposing the move, putting the Trump administration's approach of using sanctions to force foreign policy changes to the test.
While Rouhani is right that it's not likely the USA can reduce Iran's oil imports to zero, the removal of the 180-day waivers will continue to erode Iran's oil exports and much-needed petrodollars it obtains from its oil sales. But it lifts the threat that those who work with the U.S. in Iraq and Lebanon, where the Guard's many subsidiaries are active, will face the full weight of USA penalties.
An Iranian Foreign Ministry spokesman blasted the United States for not extending waivers it had given to some countries to get around its sanctions regime against Iran - and Arabic oil exporters who welcomed the decision.
When the administration of Donald Trump imposed the sanctions on April 15, there was a fear that military officials and USA diplomats would have to cut contact with officials in countries that have dealings with Tehran and the guards force.
He added: 'We need to speak to the Foreign Office about it. "We call on Iran to free all unjustly detained and missing USA persons, including Xiyue Wang, Robert Levinson, Siamak Namazi, and Nizar Zakka, among others".
"But the United States should know that when they enter the Strait of Hormuz, they have to talk to those protecting the Strait of Hormuz - and that is the Iranian Revolutionary Guards", he said. "I'm ready to do it", he said.
In the second notice, he said the sanctions would not apply "to any business, organization, or group, whether public or private, exclusively based on its provision of material support to any foreign government sub-entity that has been designated as a foreign terrorist organization".
Defiant Trump vows to fight House Democrats' subpoenas
On Monday, Trump sent a tweet with a similar message. "They have been holding out for this mystical Mueller report for two years. But she remained cautious, saying "whether it's articles of impeachment or investigations, it's the same obtaining of facts".
In the second notice, he said the sanctions won't apply "to any business, organisation, or group, whether public or private, exclusively based on its provision of material support to any foreign government sub-entity that has been designated as a foreign terrorist organisation".
As a result of the tightening of sanctions, Iran's oil exports have fallen to some 800,000 barrels a day - from the previous 2.5 million - while the national currency, the rial, has fallen sharply.
"I call them the 'B-team", Zarif quipped several times during his speech.
Oil prices eased after Brent touched $75 per barrel on Thursday for the first time in almost six months on the suspension of some Russian crude exports to Europe as investors second-guessed the market's ability to rally further.
The extended rise in prices would come as efforts by Saudi Arabia to make up for oil lost from Iran reduces the world's spare crude output capacity, the economists, led by John Payne, said in a Wednesday note.
That act, passed in the Obama administration, provides legal authority to impose sanctions on Iran's petroleum industry and foreign countries that do business with it.
"Iranians are allergic to pressure", he said, adding that he believes the conflict can be resolved diplomatically. But it said Iran should immediately release the Americans wrongfully detained first, and said any Iranians detained in the United States have been indicted or convicted of violating U.S. laws. His comments, made on Wednesday, were reported in state media and cited by the Reuters news agency.