WASHINGTON: The U.S. secretaries of state and defense on Tuesday called on all sides in the dispute between Qatar, Saudi Arabia and the United Arab Emirates (UAE) to calm tensions among the Gulf Cooperation Council (GCC) members.

"It is critical that all parties minimize rhetoric, exercise restraint to avoid further escalation and work toward a resolution," Secretary of State Rex Tillerson said at a joint appearance of the U.S. and Qatari foreign and defense ministers.

Last June the UAE, along with Saudi Arabia, Bahrain and Egypt, cut off travel and trade ties with Qatar, accusing it of supporting terrorism and their arch-rival Iran. Doha denies the charges and says the countries aim to curtail its sovereignty.

"A united Gulf Cooperation Council bolsters our effectiveness on many fronts, particularly on counterterrorism, defeating ISIS Daesh, and countering the spread of Iran's malign influence," said Defense Secretary James Mattis, referring to the Islamic State militant group sometimes called ISIS or ISIL.

"It is thus critical that the GCC recovers its cohesion as the proud Gulf nations return to mutual support through a peaceful resolution that provides for enhanced regional stability and prosperity," he added.

The two men spoke along with their Qatari counterparts after the first of what is to become an annual U.S.-Qatar Strategic Dialogue. The GCC's members, all of whom are U.S. partners, are Bahrain, Oman, Kuwait, Qatar, Saudi Arabia and the UAE.

Qatar is host to U.S. and international forces at Al Udeid Air Base, which is home to the Combined Air Operations Center. The operation coordinates an array of data and intelligence from satellites, drones, radar and U.S. planes flying over Middle East hot spots and bombing Islamic State positions.

(Reporting By Arshad Mohammed; Editing by Chizu Nomiyama and Andrew Hay) ((arshad.mohammed@thomsonreuters.com; +1 202 898 8300; Reuters Messaging: arshad.mohammed.thomsonreuters.com@reuters.net))