The United States has deployed thousands of marines and paratroopers to the Middle East and is considering ground operations to recover 440 kilograms of highly enriched uranium that disappeared after U.S. strikes against Iran last June. The deployments include marines from the 31st and 11th expeditionary units aboard navy amphibious ships from Asia, along with roughly 2,000 paratroopers from the 82nd Airborne Division.

The 82nd Airborne paratroopers are tasked with deploying worldwide within 18 hours of notification and executing parachute assaults against defended airfields to prepare for ground operations. The U.S. is weighing options to send in special forces backed by larger deployments of airborne troops or marines to search for and recover the material in Iran.

"People will have to go and retrieve the highly enriched uranium," Secretary of State Marco Rubio said. He also said that the U.S. believes it will be able to achieve its goals without boots on the ground.

Recovering the uranium would take weeks, cover multiple military sites and be dangerous for U.S. troops given Iran's experience with asymmetric warfare. The U.S. troop deployments to the region are fewer than those used in past major operations, including in Iraq and Afghanistan.

"There is concern in the Trump administration about U.S. casualties, making large-scale use of U.S. ground forces unlikely," said Max Boot, a foreign policy analyst and historian.

President Donald Trump said that the U.S. has almost won the war with Iran even as he considers sending more troops to the Middle East. Trump delayed plans to destroy Iran's power plants until April 6 as negotiations continued.

The 1980s saw Trump say he would attack Kharg Island if Iran fired on U.S. ships. Kharg Island is a coral outcrop of less than 9 square miles off Iran's coast where about 90 percent of Iran's crude oil exports flow.

Qeshm Island, the largest island in the Persian Gulf at nearly 560 square miles, serves as a storage site for Iranian attack craft, drones, sea mines and other materiel used to disrupt shipping. Larak Island is a hub for Iranian weapons used to maintain the choke point over shipping in the Strait of Hormuz.