Donald Trump's national security advisor refused on Sunday to say whether the United States would punish European companies that do not cease their business operations in Iran by the end of this year.

Companies within affected industries between 90 days and six months to wind down operations in Iran or run the risk of facing stiff penalties now that the United States is no longer a party to an international accord that lifted sanctions on Tehran.

National Security Advisor John Bolton said on CNN's 'State of the Union' that 'it's possible' the Trump administration will impose sanctions on companies that run afoul of the new U.S. policies.

'It depends on the conduct of other governments,' he stated.

Donald Trump's national security advisor refused on Sunday to say whether the United States would punish European companies that do not cease their business operations in Iran by the end of this year

European leaders are committed to remaining in the agreement with Tehran that lifted economic sanctions on the Middle Eastern country so long as it abided by the terms of a 2015 nuclear deal.

But a host of companies are now faced with the prospect of doing business with U.S. or protecting their interests in Tehran.

In his remarks announcing the United States' withdraw from the deal, President Trump threatened, 'We will be instituting the highest level of economic sanction. Any nation that helps Iran in its quest for nuclear weapons could also be strongly sanctioned by the United States.'

Bolton said in a briefing with reporters immediately after the Tuesday announcement that it would be up to the Treasury Department to determine which affected companies, if any, would get a pass.

British Prime Minister Theresa May raised the issue in a Friday phone call with Trump, a spokesperson for the European leader said.

'The Prime Minister reiterated the Government's position on the Iran nuclear deal, noting that we and our European partners remain firmly committed to ensuring the deal is upheld, as the best way of preventing Iran from developing a nuclear weapon.

'The Prime Minister raised the potential impact of US sanctions on those firms which are currently conducting business in Iran.'

Donald Trump last night tore up the Iran nuclear deal, which could force Britain's biggest businesses out of the country

Major British businesses with interests in Iran include Rolls-Royce, Vodafone and British Airways. UK companies have invested £450 billion into Tehran since the U.S. and Europe lifted sanctions after the signing of the accord with partners Russia and China.

Finance ministers in France and Germany pushed Treasury Secretary Steven Mnuchin to grant extensions or waivers to businesses that made lucrative deals with Tehran in the period that sanctions were lifted.

Bruno Le Maire, the French finance minister, said European states will also try to impose sanctions-blocking measures through the European Commission.

'Do we accept extraterritorial sanctions? The answer is no,' Le Maire said.

'Do we accept that the United States is the economic gendarme of the planet? The answer is no. Do we accept the vassalization of Europe in commercial matters? The answer is no.'

Le Maire is seeking exemptions for Renault, Total, Sanofi, Danone and Peugeot and other companies already doing business with Tehran.

Trump's new ambassador to Germany, Richard Grenell, suggested that exemptions were unlikely, saying Thursday, 'German companies doing business in Iran should wind down operations immediately.'

European companies did not have an immediate have a reaction to possibility that they would have to cease operations in Iran or be barred from doing business with the U.S. other than to say in statements that they were monitoring the situation.

'We are examining the announcement and its potential implications,' Rolls Royce said. 'We conduct business in all countries, including Iran, in accordance with all relevant UK, EU or other national sanctions and export control regulations.'

British Airways, which operates six flights a week between London Heathrow and Tehran, said, 'We constantly review our network to ensure that our routes match our customers' needs and are commercially viable. ​ ​We are in regular contact with the Foreign and Commonwealth Office.'

Trump's tough talk now on sanctions is at odds with what he told France's Emmanuel Macon and May just six months ago as he moved toward yanking the U.S. out of the deal.

He said in October that he told the allies 'take all the money you can get' from Tehran.

'Actually, Emmanuel called up, and he talked to me. And I said, look, Emmanuel, they just gave Renault a lot of money. Take their money; enjoy yourselves,' Trump said then.

The U.S. president said that the European leaders wanted him to stay in the deal he'd said he'd exit since he was a candidate because of the financial implications of leaving it.

'You know, Iran is spending money in various countries. And I've always said it, and I say to them: Don't do anything. Don't worry about it. Take all the money you can get. They're all friends of mine,' Trump said.