Washington re-introduced sanctions against Iran on November 5, restoring measures lifted under a 2015 nuclear deal negotiated by the administration of President Barack Obama, and adding 300 new designations including Iran's oil, shipping, insurance and banking sectors.
The US sanctions herald the end of Washington's involvement in the landmark 2015 deal signed between Iran, the US and other world powers, which was created to curb Iran's nuclear ambitions.
They aim to significantly reduce Iran's oil exports - which have already fallen by around one million barrels a day since May - and cut it off from worldwide finance.
Countries that continue to import Iranian oil and do not have a U.S. waiver risk USA sanctions forbidding Americans from doing business with their companies and cutting off access to the United States financial system.
"America wanted to cut to zero Iran's oil sales. but we will continue to sell our oil.to break sanctions", Rouhani told economists at a meeting broadcast live on state television.
In a statement, US Treasury Secretary Steven Mnuchin said the move "should make clear to the Iranian regime that they will face mounting financial isolation and economic stagnation until they fundamentally change their destabilising behavior". Over 700 entities were targeted, according to CBS News; some of the sanctions had been imposed by the Obama administration but were canceled when Obama signed on to the Iran nuclear deal.More news: Lowe's to close two mid-Michigan stores
The US wants to shut down Iran's crude oil exports with the embargo.
Keen said the European Union was also looking to implement a payment mechanism via a Special Purpose Vehicle to handle transactions with Iran and avoid payments directly into or out of Iran.
"We are in the economic war situation".
United States president Trump has taken a hardline against Iran since taking office.
Aside from restrictions on oil imports, the administration added more than 700 names - including individuals, entities, vessels and aircraft linked to the energy and financial sectors and other segments of Iran's economy - to the United States list of sanctioned entities.
Iran has strongly denounced the U.S. policy. However, the USA has granted eight temporary waivers to countries that will let them wind down their imports over time. "We're working with other countries to get alternative supplies for countries that are buying and I think that's critical over an extended period of time".
"Rest assured, Iran will never come close to getting a nuclear weapon on President Trump's watch", Pompeo said.
He spoke to a conference of economists, who he said were at the "forefront of the resistance" against the United States. "If the sanctions are prolonged, it will be a factor (in causing production costs to increase)", said one official from a local petrochemical company.