Iran's foreign minister Mohammad Javad Zarif called on Sunday for a united front among Middle Eastern nations to fight militancy, in his first regional trip since Iran reached an agreement with world powers on the country's nuclear programme - an agreement that raised fears among its Gulf Arab neighbours. Most Gulf Arab states are worried that Iran's July 14 accord will hasten detente between Tehran and Washington, emboldening Tehran to increase backing for Middle Eastern allies at odds with Gulf Arab countries. Most Sunni Muslim-ruled Gulf Arab states have long accused Tehran of interference in Arab affairs, alleging financial or armed support for political movements.