French oil major Total may turn its back on its $1bn (£740m) Iranian gas project within six months unless it can clinch a sanctions waiver for the project from the USA government.
"In the case of oil purchases from Iran", Bolton said, "if it's a long-term requirements contract. what we're saying is that although the sanctions come back into effect immediately, precluding any new contracts, for those affected by our jurisdiction, they've got six months to phase it out".
But big European companies simply aren't willing to take the risk of continuing to invest and operate in Iran.
"Total has always been clear that it can not afford to be exposed to any secondary sanction which might include the loss of financing in dollars by U.S. banks for its worldwide operations, the loss of its USA shareholders or the inability to continue its United States operations", the company said.
Total's $2 billion deal with Tehran was in partnership with Petrochina, a subsidiary of China's largest oil and gas company, CNPC.
Continuing to do business in Iran would be too great a risk as the company has large operations in the US and depends on the country's banks for financing its operations, Total said in a statement Wednesday.
Iran has said it may start enriching uranium again if it can no longer see any economic benefit to the deal. "They have us by the throat because so much business is conducted and cleared in dollars", one European investment banker said. The U.S. Treasury has given companies up to 180 days to end dealings with Iran.
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Germany's Allianz, an insurance giant with a major presence in the United States, said it intends to wind down what it called its "totally minimal" business in Iran.
In addition, about 14 million barrels of oil products were purchased from, or sold to, entities with ties to the Iranian government, generating 1.1 billion euros of revenue, and a net loss of 5.7 million euros, according to Total.
Another Danish oil tanker operator Torm has said it would stop taking new orders in Iran.
But the reach of the US financial system, the dominance of the dollar and the presence of European companies' operations in the United States all weaken any potential EU counter-measures. The deal also restarted foreign trade and investment flows into Iran.
Total's move is likely to rattle European governments and the European Commission, which warned Trump against acting to punish their businesses operating in Iran under the legitimacy of the nuclear deal they helped broker.
But Mogherini said the European Union would make every effort to maintain business ties with Tehran and ensure that Tehran can continue to sell its oil around the world. The sanctions target the Iranian energy industry, and could penalize companies and individuals that do business with Iran.
"The current situation will pass and Iran will emerge as a victor", the oil ministry's news agency SHANA quoted Zanganeh as saying.