The commander of Iran's elite Revolutionary Guards said on Wednesday: "We are on the cusp of a full-scale confrontation with the enemy," the Fars news agency reported.Major General Hossein Salami, named head of the force last month, added: "This moment in history, because the enemy has stepped into the field of confrontation with us with all the possible capacity, is the most decisive moment of the Islamic revolution."The United States has sent further military forces to the Middle East, including an aircraft carrier, B-52 bombers and Patriot missiles, in a show of force against what U.S. officials say are Iranian threats to its troops and interests in the region.