The lifting of nuclear-related sanctions is an essential part of the deal - it aims at having a positive impact not only on trade and economic relations with Iran, but most importantly on the lives of the Iranian people.
Pompeo said the United States will enforce sanctions as long as Tehran keeps up its "malign activity".
Iran says the sanctions are endangering lives by blocking the sale of new planes and spare parts for its ageing fleets.
Iran will ease foreign exchange rules in a bid to halt a collapse of the rial currency, which has lost half its value since April due to fears about the return of USA sanctions, according to state media reports on Sunday. By nearly all accounts, the wide spectrum of USA and multilateral sanctions were responsible for getting Iran to the negotiating table.
That came only a few days after a bellicose exchange between the two presidents, with Rouhani warning of the "mother of all wars" and Trump responding with a Twitter tirade against Iran's "DEMENTED WORDS OF VIOLENCE".
"There is a massive loss of confidence in the financial system and the government's ability to control things and withstand sanctions", she said.
Iran wants guarantees from Europe to maintain banking cooperation and investments in Iran's oil fields as well as continuation of cooperation between Iranian and European small and medium-sized enterprises, Qasemi noted.
Iranian Foreign Minister Mohammad Javad Zarif speaks to the media in Tbilisi, Georgia, April 18, 2017. That's what America is trying to get Iran to stop doing.
Israel supported the imminent resumption of USA sanctions. Mindful of the high cost, some foreign businesses that took advantage of the diplomatic breakthrough have begun winding down their operations in Iran.
French carmaker Renault, which does not sell cars in the USA, has said it will remain in Iran despite the sanctions. He insisted that most diplomats at the Singapore summit agree with the United States.
Iranian President Hassan Rouhani said last week that Mr Trump's repudiation of the deal was illegal and Iran would not yield to Washington's renewed campaign to strangle its vital oil exports. "That's the ask. It's pretty simple".
The United States has told other countries they must halt imports of Iranian oil starting in early November or face USA financial measures.
Hemmati had told state TV late on Sunday that "money exchangers are allowed to sell and buy foreign currencies" once again, to help Iranians get better access to "services and travel overseas".
"We're happy to talk, if there's an arrangement that is appropriate, that can lead to a good outcome", Pompeo said. "Perhaps that will be the path the Iranians choose to move down with. But there's no evidence today of a change in their behavior".
Pompeo said the White House would make an announcement on Monday detailing the reinstatement of some sanctions on Iran. "They're unhappy with the failure of their own leadership to deliver the economic promises that their leadership promised them".