In a message mainly aimed at skeptical voices in the U.S. Congress and strong resistance from Israel, EU foreign ministers meeting in Brussels stressed that there was no better option available.
Ministers left the details of their endorsement until after a U.N. Security Council vote scheduled for 9 a.m. EDT (1300 GMT), but have formally committed to a gradual lifting of sanctions along with the United States and the United Nations.
The U.S. Congress received the Iran nuclear agreement on Sunday and will have 60 days from Monday to decide whether to approve or reject the deal.
Keen to consider Iran as an alternative supplier of energy at a time of tensions with Russia, the European Union may reopen an EU delegation in Tehran and is seeking business opportunities in the country, Reuters said.
'The Iran deal has a geopolitical impact and also an economic impact on the European Union,' said Austria's Foreign Minister Sebastian Kurz, who plans to visit Iran in September.