President Donald Trump has cancelled a planned attack on Iran after reaching an agreement over the 'perimeters of a deal'. The agreement includes the immediate opening of the Strait of Hormuz and an end to Iran's nuclear threat. Despite reports that the U.S. was preparing for a fresh round of strikes against Iran as early as this weekend, the president has agreed to cancel the attack. U.K. Embassies in the Middle East have warned American citizens in the region to exercise caution and be prepared for flight cancellations due to tensions between Iran and the United States. Key sticking points include Iran's nuke program and control of shipping through the Strait Hormuez, where about a fifth of the world's oil supplies moved.