White House national security adviser John Bolton said on Sunday US sanctions on European companies that maintain business dealings with Iran were "possible" although Pompeo has remained hopeful Washington and its allies could strike a new nuclear deal with Tehran.
The EU won't walk away from the Iran nuclear deal even if Donald Trump wants to kill it, the bloc's top diplomat said.
"I think that will sink in; we'll see what happens then", Bolton said.
Iran is seeking assurances that European, Russian and Chinese companies will continue to do business with Iran, even in the face of threats that such companies might have to face U.S. sanctions. "It depends on the conduct of other governments".
Trump declared last week that the United States would withdraw from the deal, claiming that it had failed to prevent Iran from developing nuclear weapons or supporting terrorism in the region.
A spokesperson for May's office said, "The Prime Minister made clear that the United Kingdom condemns the Iranian missile attacks against Israeli forces and called on Iran to refrain from any further attacks".
Supporters of the deal say that Iran has complied with its requirements, and insist it is the only realistic alternative to military force as a means of halting Tehran's nuclear program.
The Iran deal, named as Joint Comprehensive Plan of Action (JCPOA), was signed in July 2015 in Vienna by USA, UK, France, Germany, Russia, China and European Union. Mohammad Javad Zarif will meet with his counterparts from Britain, France and Germany-the three European nations involved in the landmark deal who are incensed by Washington's abandonment of the pact. "The answer is no", Le Maire told reporters in Paris, adding that France won't accept the "vassalization of Europe" by US officials bent on reimposing sanctions on Iran.
But Secretary of State Mike Pompeo said Washington was keen to thrash out a more wide-ranging deal with its European partners.
Mr Johnson revealed on Monday that he would discuss ways to protect them during a meeting with fellow foreign ministers from France and Germany on Tuesday.
According to Zarif, the objective of his trip is to get guarantees from the other participants of the nuclear deal that the interests of Iran will be protected.
Many European diplomats doubt privately that the 2015 accord between Iran and six world powers can survive the reimposition of US sanctions ordered by Trump, but the European powers will say that they stick by the terms of the 2015 pact giving Iran sanctions relief in return for an end to its nuclear ambitions.
French Finance Minister Bruno Le Maire said Friday on Europe-1 radio that Europe should not accept that the U.S.is the "world's economic policeman".
The first-ever meeting between a North Korean leader and a sitting US President reflects the significant progress that has been made in the space of just a few months.
Trump's abrogation of the JCPOA will nearly certainly fuel the downward spiral of confrontation in the Middle East, while further complicating matters on the Korean Peninsula. It cited, for instance, Trump's earlier dumping of the Paris climate change agreement with a promise to provide a better deal that he hasn't fulfilled.
As for the assurances, Mogherini said, "I cannot talk about legal or economic guarantees but I can talk about serious, determined, immediate work from the European side".