Several hundred U.S. Special Operations forces have arrived in the Middle East, joining thousands of Marines and Army paratroopers in a deployment aimed at expanding options for President Trump's war with Iran, according to U.S. military officials. The commandos, including Army Rangers and Navy SEALs, have not yet been assigned specific missions.

Military officials say the specialized ground troops could be deployed to safeguard the Strait of Hormuz, which Iran has effectively closed, or potentially seize Kharg Island, Iran's oil hub in the northern Persian Gulf. The Pentagon has also ordered about 2,000 soldiers from the Army's 82nd Airborne Division to the region, bringing total U.S. troop presence to more than 50,000.

The Strait of Hormuz, through which around 20 percent of the world's oil usually traverses, has been largely closed because of Iranian attacks retaliating against U.S. and Israeli actions. Military experts caution that even 50,000 troops are insufficient for a major land operation in Iran, which has 93 million people and is almost a third the size of the continental United States.