The three European allies and Russian Federation are trying to keep the landmark 2015 accord alive in the wake of U.S. President Donald Trump's decision, pushing Moscow into rare cooperation with Europe.
Mohammad Javad Zarif's reserved optimism is evident in his statement on the arrival in Beijing.
"We think that the fight against nuclear non-proliferation is important and this agreement means that nuclear non-proliferation is possible because Iran will not go all the way to nuclear weapons", Le Drian told reporters in Dublin. "Our meetings will continue during the upcoming two weeks".
Iran said it would remain committed to the deal without Washington if Tehran achieved its goals - namely being protected from sanctions against key sectors of its economy such as oil - in cooperation with other countries that have signed up to the agreement.
That is part of a flurry of diplomatic activity following Trump's unilateral withdrawal from what he called "a terrible, one-sided deal", a move accompanied by the threat of penalties against any foreign firms doing business in Iran. It's unclear how well the measure could be enforced, given that big multinationals are likely to be doing more business in the USA than they are in Iran and may be unwilling to compromise that market access.
He also acknowledged that the USA sanctions against Iran could affect European companies, which shows "how difficult" the situation was to resolve, said Roth.
"We are waiting now for how the decision-makers in the European Union will react".
Zarif will then travel to Brussels for talks with the European countries that are party to the JCPOA on the possibility of preserving the accord with Iran's interests at its heart.
While announcing his decision, Trump called the agreement "defective at its core", claiming that after the lifting of the sanctions Tehran "used its new funds to build nuclear-capable missiles, support terrorism and cause havoc throughout the Middle East and beyond".
The sanctions will target critical sectors of Iran's economy, including petrochemicals, energy and finance.
Zarif said European powers must give Iran guarantees that it will get the economic benefits of the deal, warning there was not much time for them to deliver those assurances. "They will never abandon the U.S. for us", said housewife Poormoslem at a protest against Trump on Friday. European companies could still face big fines, asset seizures and even criminal charges in the US.