Iran's foreign minister on Tuesday hailed talks with the European Union to try to find a way to rescue the Iran nuclear deal after the U.S. pulled out as a "good start".
One of the crucial points of discussion will be about how to maintain economic relations and effective banking transactions with Iran in the context of renewed U.S sanctions, according to European Union (EU) foreign policy chief Federica Mogherini.
Zarif's meetings in Brussels capped a whirlwind global tour, including trips to both Russian Federation and China, the two other signatory nations, in a bid to bolster support.
Trump opted not to extend sanctions relief on Iran ahead of a May 12 deadline, vowing instead to re-impose nuclear-related economic penalties.
Under the new regulations, US authorities will close existing USA accounts - or prohibit the opening of any new accounts - belonging to any foreign bank that processes payments through Iran's central bank for any transaction, not just oil deals.
French oil giant Total signed a $5bn contract with the National Iranian Oil Company in July 2017 for the development and production of phase 11 of South Pars, the world's largest gas field.
Mr. Lavrov, for his part, said Russian Federation and Europe had a duty to "jointly defend their legal interests" in terms of the deal.
Major European powers have sought to keep Iran in a landmark worldwide nuclear agreement after President Donald Trump pulled the US out of the pact and promised tough economic sanctions against Tehran.
Iran has ordered negotiations to begin with the remaining parties in an effort to salvage the agreement.
Zarif is further scheduled to conduct a number of worldwide diplomatic meetings to discuss the deal with global leaders.
Washington has shot itself in the foot by announcing the upcoming resumption of anti-Iranian sanctions, as Chinese and European investors are already seeking to circumvent United States restrictions.
The European Commission discussed possible ways to preserve the 2015 nuclear accord and EU leaders will continue the discussion at a dinner in Bulgaria, Avramopoulos said.
"What was significant is that Zarif reaffirmed their will to stick to the agreement if we find a way to help them a little", a senior European diplomat said.
This, along with its diplomatic moves to orchestrate an end to the Syrian conflict, has put Moscow at loggerheads with the USA and Europe, which have intervened against the regime.
British Prime Minister Theresa May, French President Emmanuel Macron and German Chancellor Angela Merkel released a joint statement condemning Trump's move while pushing Iran to "continue to meet its own obligations under the deal".