The Pentagon on Tuesday scoffed at the claims by Iran's Revolutionary Guards that U.S. carriers were "easy targets" for its swarm boats and could sink a U.S. warship in less than a minute.

The U.S. Navy was "wholly unconcerned" by the boasting of Adm. Ali Fadavi, the Guards' hard-line naval chief, who said that Iran was building a mockup of the carrier Nimitz for target practice, said Army Col. Steve Warren, a Pentagon spokesman.

Warren said he had seen the carrier mockup in the Iranian port of Bandar Abbas on satellite imagery. He dismissed Fadavi's claims that his missile-equipped small boats could sink a U.S. warship in 50 seconds.

"My guess is he could sink the mockup in 50 seconds," Warren said.

In an interview with Iran's Fars news agency, Fadavi said "the Americans and the entire world know that one of the operational goals of the IRGC (Iranian Revolutionary Guards Command) Navy is the destruction of the U.S. Navy."

Fadavi confirmed Iranian newspaper reports that Iran's navy was constructing a replica of the Nimitz for gunnery practice.

"We have been making and sinking replicas of U.S. destroyers, frigates and warships for many years, and we have sunk the replica of their vessels in 50 seconds through a series of operational measures," Fadavi said.

As backup for his claims that carriers were "easy targets," Fadavi cited the recent book "Duty" by former Defense Secretary Robert Gates.

"If you take a look at Robert Gates' book, you will see that he openly recounts the vulnerabilities of aircraft carriers to the IRGC Navy and his demand is that the US naval strategy must change," Fadavi said.

Fadavi's claims were also dismissed by Cmdr. Jason Salata, a spokesman for the Navy's 5th Fleet headquartered in Bahrain.

"Whatever Iran hopes to do with the mockup, it is likely to have zero impact on U.S. Navy operations in the Gulf," Salata said in a statement.

"Firing weapons at a stationary structure floating on pontoons is not a realistic representation of having the capability to target a 100,000-ton warship maneuvering at speeds in excess of 30 knots," Salata said.

Fifth Fleet commanders have previously stated during operations in the Persian Gulf and the Strait of Hormuz that their contacts with Iran's navy have been cordial and professional – in contrast to the sometimes difficult communications with the small boats of the Revolutionary Guards.

Fadavi's bellicose statements contrasted with the policies of President Hassan Rouhani in negotiating with the U.S. and the West on reining in Iran's nuclear programs.

-- Richard Sisk can be reached at richard.sisk@monster.com