Iranian media reported the country's military conducted a second day of test-firing missiles, but the U.S. military official told CNN U.S. radar and satellite imagery don't support the claim.
The military official said it was possible that Iran tested short-range missiles.
U.S. diplomatic and military officials said they believe Iran did fire seven missiles -- including one long-range Shahab-3 -- Wednesday, as it said. But the source talking to CNN said one missile failed to launch and the Iranians fired it the following day.
The Iranian exercises came a month after Israel conducted a military drill in the eastern Mediterranean. Tensions between Iran and Israel have been growing. Iran has accused Israel of trying to weaken Tehran while Israel hasn't ruled out a military strike against Iran's nuclear facilities.
Israel was expected to unveil an advance aircraft its military said is capable of spying on Iran. Israeli Army Radio told CNN the Eitam airplane is a "practical answer" to recent Iranian "threats."