The two officials "discussed the ongoing work towards implementation day and took stock of the important progress made so far," the EU External Action Service (EEAS) said in a statement.
The phone call came hours after a major crisis broke out in the Middle East following the execution of a prominent Shiite cleric by Sunni authorities in Saudi Arabia.
On July 14, Tehran and a group of six international mediators hammered out a deal that has seen Iran dismantle parts of its nuclear infrastructure in exchange for sanctions easing.
The accord, known as the Joint Comprehensive Plan of Action, guarantees the peaceful nature of Iran's nuclear program and sets out key nuclear commitments that Iran must take before sanctions are scrapped over the next few years.
