By Mike Mount

Iran is steadily improving its missile capability and could be able to test a missile that could reach the U.S. shores within three years, according to a new Pentagon report assessing the status of the Iranian military.

"Iran has boosted the lethality and effectiveness of existing systems with accuracy improvements and new submuntion payloads," which allows missiles to drop explosives over a wider area causing more destruction, according to the report.

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The missiles were part of war game exercises conducted by Iran last week. Iran's government said it was testing missiles capable of hitting U.S. bases around the Middle East.

"During the war games, long-range, medium-range and short-range missiles will be used and will be fired from different points across the country," which an Iranian spokesman said was designed to test the precision and efficiency of the warhead and missile systems.

The Pentagon report was created in April, ahead of the most recent Iranian war games, so intelligence from those exercises was not included in the report. Additionally, U.S officials could not confirm the accuracy of the Iranian statements about the latest exercises.

The latest report did cite Iranian war games held in 2011 in which Iran launched several missiles, "including a multiple missile salvo."

The 2012 report was signed by Defense Secretary Leon Panetta and sent to defense committees on Capitol Hill last week. It said regular ballistic missile training continues throughout the country and continues to develop missiles that can hit Israel and Eastern Europe, including an extended-range Shahab-3 and a medium-range ballistic missile, called the Ashura, that can fly more than 1,200 miles.

The report repeats what has been stated publicly by the United States, that over the last 20 years Iran has "placed significant emphasis on developing and fielding ballistic missiles," that could threaten the United States, coalition and partner countries around the Middle East and to project power in the region.

The report also maintains that Iran is still capable of testing a long-range intercontinental ballistic missile by 2015, "with sufficient foreign assistance."

The United States and NATO have begun to field an anti-ballistic missile shield in the southern and eastern parts of Europe to protect from such a threat.

But weapons analyst John Pike said the missile shield is not fully operational.

"You know 2015 is very soon. Certainly if you believe the 2015 forecast, Iran would have that ballistic missile before the United States has a defense against it," Pike, weapons expert at GlobalSecurity.org, said on Wednesday.

Regarding Iran's continued desire to develop a nuclear weapon, the report reiterated already released information and positions the United States has held, but tied Iran's nuclear desires to Iran's ballistic missile ambition under the topic "Iranian Capabilities related to Nuclear and Missile Forces." That emphasized the over-arching threat the United States sees: Iran ultimately putting a nuclear weapon on an intercontinental ballistic missile.

Iran has also claimed to have deployed anti-ship, short-range ballistic missiles that can identify and maneuver toward ships as they fly, according to the report. After Iran's continued saber-rattling and the country's threats to close the Straight of Hormuz, the United States moved a floating base for naval special forces into the Arabian Gulf, as well as four anti-mine ships.