The Joint Comprehensive Plan of Action is a "good" and "robust" agreement, EU Foreign Policy Chief Federica Mogherini said.
"The Iran deal is a good and robust agreement that serves the interests of all parties," she said in a statement to NBC News.
She recalled that the nuclear deal's achievement belongs to the international community and not just the US.
"It is not an agreement between two countries – it is a commitment undertaken by the entire international community on one side and Iran on the other, supported by a resolution of the UN Security Council,” Mogherini stressed.
The EU will make sure that all the sides of the agreement are sticking to their obligations, Mogherini said.