Mogherini's first stop will be Saudi Arabia on Monday, where she will meet officials including the country's new foreign minister Adel al Jubeir, with whom she is expected to discuss regional issues following the July 14 nuclear accord with Iran.
Mogherini will then go on to Iran, where she will meet Iranian Foreign Minister Mohammed Javad Zarif and other senior officials.
Read: Iran leader tells Rouhani 'some' world powers untrustworthy
The European Union formally approved this week the deal it struck with Iran and other world powers, a step toward lifting its economic sanctions against Tehran, which the bloc hopes will send a signal for the U.S. Congress to follow.
Mogherini follows on from German Vice Chancellor Sigmar Gabriel's visit to Iran at the start of this week, the first senior figure from a large Western government to visit the country since the deal.
Read: A decade in the making: The deal is sealed
France's Foreign Minister Laurent Fabius and other European foreign ministers are due to travel there soon.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ