President Donald Trump is weighing whether to order the U.S. military to get directly involved in Israel’s war against Iran, though experts warn it is unclear if the United States’s most powerful bomb would be capable of destroying Iran’s most hardened nuclear enrichment facility.

The Defense Department has rushed additional weapons and personnel to the Middle East this week as Israel and Iran continue to exchange volleys of airstrikes and missile attacks. So far, U.S. forces have only aided Israel in defending itself from incoming Iranian-fired projectiles, though Israel is hoping for the U.S. to join it in offensive operations.