Pentagon calls for 'urgent' upgrade of massive bunker-busting bombs, as Iranian threat looms

The military's so-called Massive Ordnance Penetrator, a 30,000-pound bunker buster bomb, requires an "urgent" upgrade, according to Pentagon officials who are trying to ensure that 20 of the bombs are battle-ready -- possibly for use against Iran, though officials have been tight-lipped on potential targets.

The Air Force developed the bomb in conjunction with Boeing to attack concrete bunkers and tunnel facilities, and the Pentagon has requested $81 million in reallocated funds from Congress to get it ready for use.

Defense appropriators on Capitol Hill agreed to the request on Wednesday, just one month after Iran announced it would begin uranium enrichment at a hardened underground facility near the city of Qom in the Fardow mountain range. The tunneled facility is thought to be beyond the range of the bunker buster in question -- the largest non-nuclear weapon in the U.S. Air Force's arsenal.

A Pentagon spokesman said the funding was needed to "make the system more survivable."

The Massive Ordnance Penetrator, or MOP, is delivered by a B-2 or B-52 bomber plane. According to Boeing, it "allows the warfighter to hold adversaries' most highly valued military facilities at risk, especially those protecting weapons of mass destruction."

Publicly, the Air Force denies this weapon is being rushed for use in the Middle East. Air Force Chief General Norton Schwartz dismissed suggestions that the upgrades are tied to tensions with Iran.

Former Rep. Ike Skelton, who once served as House Armed Services chairman, was at the Pentagon on Friday to dedicate a new Navy ship in the name of former Rep. Gabrielle Giffords. He was asked whether the MOP faced problems when his committee was responsible. He said, “no,” adding that the U.S. has the conventional firepower to stop Iran's nuclear program.

Meanwhile, Israel successfully tested upgraded radar for its Arrow Missile Defense shield that it jointly developed with the Pentagon. The Blue Sparrow 2 missile was fired from an undisclosed location deep in the Mediterranean Sea towards Israel.

The test comes just days after Iran tested its Shahab 3 missile, which is capable of hitting Israel, and on the same day that Hamas leader Ismail Haniyeh was in Tehran to improve ties.