"No unilateral steps. We invite all to de-escalate tensions and engage in direct dialogue," Mogherini told reporters before the meeting of the foreign ministers of the EU member states in Luxembourg, adding that "any difficulties and tensions can and must be solved at the table by dialogue and politically."
Mogherini also stressed that the European Union was directly interested in the Gulf countries' cooperation with each other.
"They are all our partners in the fight against terrorism. They are all our partners economically. But they are all our partners in trying to solve some of the regional crises," the EU chief diplomat said.
Mogherini also reaffirmed the EU's support for Kuwaiti mediation efforts in resolving the crisis.
On June 5, a diplomatic crisis erupted in the Middle East when Saudi Arabia, the United Arab Emirates (UAE), Bahrain and Egypt broke off their diplomatic ties and other communication with Qatar, accusing Doha of supporting terrorism and interfering in their internal affairs.
The rift continued when the Maldives, Mauritius, and Mauritania also announced the severance of diplomatic relations. Later, Jordan and Djibouti reduced the level of their diplomatic missions in Qatar, and Senegal, Niger and Chad withdrew their ambassadors from Doha.