"I believe it's a good start". "We talked about the need to do this exercise in the next few weeks". "A lot depends on what we can do within the next few weeks".
He admitted though that U.S. sanction would "serve as a deterrent to businesses".
But she added: "Normally when we work together - committed, determined, with good faith and good will, even in hard circumstances - we get to good achievements".
Said Iran's Zarif: "We are on the right track". Those included continuing to sell Iran's oil and gas products, maintaining effective banking transactions and protecting European investments in Iran.
The European Union insists the deal is working, pointing to repeated United Nations inspections verifying the Islamic republic's compliance with its side of the bargain.
EU President Donald Tusk said in a letter to EU leaders on May 15 that the summit would "reflect on recent global developments, in particular following President [Donald] Trump's announcement on Iran and trade".
"I would like our debate to reconfirm without any doubt that as long as Iran respects the provisions of the deal, the European Union will also respect it", Tusk said in a letter to the leaders on the eve of the summit.
The United States on Tuesday imposed sanctions on Iran's central bank governor and others, accusing them of involvement in funding the Shia Muslim group Hezbollah.
German exports to Iran totalled almost 3.0 billion euros in 2017, while French exports soared from 562 million euros in 2015 to 1.5 billion in 2017 and oil giant Total has pledged to invest some $5 billion in the South Pars gas field.
The EU's top energy and climate official, Commissioner Miguel Arias Canete, is heading to Iran on May 18-21 for talks on energy cooperation, a symbolic gesture from the EU that it wants to stay engaged despite the US withdrawal.
Iranian Foreign Minister Mohammad Javad Zarif called the U.S. actions an indication of weakness.
The steps forward underscored the EU's hopes that diplomacy and the promise of economic benefits might keep Iran in the fold of a nuclear deal that Europe sees as essential to security.
The French firm signed a deal with Tehran in July 2017 to develop phase 11 of Iran's South Pars field, marking the first major Western energy investment in the long isolated country since the lifting of sanctions.
German Federal Chancellor Angela Merkel criticized in the lower house of parliament (Bundestag), the withdrawal of the U.S. government from the nuclear agreement with Iran.
"We are working on finding a practical solution", she told a news conference in Brussels.