Many of these companies initially were targeted by sanctions under President Barack Obama, but the restrictions were subsequently lifted when the US struck a deal with Iran in 2015 over its nuclear ambitions.
Iran's foreign ministry is shrugging off the re-imposition of USA sanctions on Iran, saying it's nothing new and that the country has gone through a wider range of sanctions in the past.
He qualified that transactions for "humanitarian" purposes would be exempt, as they had been in the past, but cautioned that "banks must be very careful that these are not disguised transactions".
US Secretary of State Mike Pompeo said on Sunday the penalties returning on Monday were "the toughest sanctions ever put in place on the Islamic Republic of Iran".
The president in May pulled out of the Iran nuclear deal made by the Obama administration.
"America wanted to cut to zero Iran's oil sales.but we will continue to sell our oil.to break sanctions", Rouhani told economists, adding the sanctions were illegal and unfair. "We are in the economic war situation".
"We have no issue with talking, if the other side can respect and live up to its promises and commitments", Rouhani stressed.
"US bullying is backfiring".
Pompeo also remarked on President Donald Trump's "sanctions are coming" message, which he tweeted out in the form of a dramatic Game of Thrones-style poster Friday.
All of the other signatories - China, the European Union, France, Germany, Iran, Russia, and the United Kingdom - have remained in the deal despite the US action.
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A person close to Miller, whose real name was Malcolm James McCormick, said he had spent the evening watching football. Miller's death came just months after he split from Ariana Grande and weeks after he was charged with a DUI.
Under US law, exceptions can be granted for up to 180 days.
The unilateral sanctions reintroduce some of the most crippling restrictions on Iran's oil, shipping and banking sectors and seek to penalise even non-US entities that do business with Iran.
"U.S. sanctions against Iran. created serious concerns with traders earlier in September".
Some of the banks designated on Monday have served as "financial conduits" for the Ministry of Defense and Armed Forces Logistics and the Islamic Republic of Iran Broadcasting, according to the USA government. As long as Iran met its obligations under the deal, Britain would be committed to it too.
Pompeo threatened that the USA would mete out "severe, swift punishment" to any nation that continues to buy Iranian oil, but granted a temporary waiver to eight countries - including China, Italy, Greece, and Turkey - to continue imports for the time being. At that time, the waivers were not official, and the eight countries were unidentified.
"Sanctions waivers being given to key purchasers of Iranian oil, most alarmingly China, give Iran a financial reprieve, and should be eliminated as soon as possible". But Brent crude was steady at $72.83 by 1230 GMT.
U.S. West Texas Intermediate (WTI) crude futures were down 27 cents, or 0.4 percent, at $62.87 a barrel.
Iran's military forces staged war exercises and its president defiantly vowed to "break" U.S. sanctions on oil sales that were reimposed today, as Tehran resisted a Trump Administration pressure campaign aimed at isolating the country economically.
The reimposition of the sanctions came as the U.S.is focused on Tuesday's congressional and gubernatorial elections.
In a speech on Saturday, Iran's Supreme Leader Ayatollah Khamenei said Mr Trump's policies faced opposition around the world.
Avigdor Lieberman said in a tweet on Monday that the Trump administration's decision to restore sanctions "is the sea change the Middle East has been waiting for". "Right now they just want to survive".