US defense officials on Monday congratulated themselves on an armored vehicle that helped protect American troops but acknowledged the program succeeded in spite of the Pentagon's own entrenched bureaucracy.

During the Iraq war, as homemade explosives inflicted heavy casualties on soldiers riding in standard Humvee vehicles, senior officers had appealed to Washington for heavier trucks better designed to withstand insurgent bombs.

But their request met with opposition in the Pentagon and in Congress, and it took a concerted push from former defense secretary Robert Gates and others to rush into production new vehicles known as MRAPs, mine resistant ambush protected vehicles, officials said.

"Commanders saw an urgent need. They requested urgent assistance from the Pentagon, a plea that initially went unheeded, a mistake that forced the department to permanently alter its whole approach to meeting urgent battlefield needs," Ashton Carter, deputy defense secretary, said at a ceremony honoring the team that pressed for the MRAP.

As Pentagon chief, Gates had voiced his "frustration with the business-as-usual approach he found too often here, and led to his decisions in many cases simply to bypass the system, as with the MRAP Task Force," Carter said.

Gates, who stepped down last year, would often lament how "the troops are at war, but the Pentagon is not," said Carter.

In a written note read out at Monday's event, Gates praised the task force he appointed -- which expedited the delivery of more than 24,000 MRAPS to troops in Iraq and Afghanistan, at a cost of roughly $45 billion.

"You have led and implemented the largest defense procurement program to go from decision to full industrial production in less than a year since World War II," he wrote.

And in a dig at the Pentagon mindset, he added: "As you look back on this unique time in your careers, you can take great satisfaction in knowing -- unlike many, even in the Defense Department -- that your work truly saved the lives and limbs of many men and women in uniform."

Vice President Joe Biden, who, as a senator, led efforts to fund the heavily-armored truck, told the audience he struggled to persuade fellow lawmakers -- including "pro-defense" hawks -- to support the initiative in 2007.

Some lawmakers criticized the proposal because they said the military would have no use for the trucks once the wars in Iraq and Afghanistan were finished, Biden said.

"Can you imagine Franklin Roosevelt being told, 'We need X number of landing craft on D-Day, but, you know, once we land we're not going to need them all again. So why build them?'" Biden said.

The Pentagon has no plans to build more MRAPs and the program will now be managed by the Army instead of the Marine Corps, a step officially marked at Monday's "transition" ceremony.

Officials say the slow-moving, heavy vehicles are expected to have a less prominent role in the future US force, once the bulk of American combat troops withdraw from Afghanistan by the end of 2014, with a large number of MRAPs due to be placed in storage.

Carter said the end of MRAP production illustrated the US shift away from counter-insurgency campaigns to a strategic tilt towards Asia.

"The era of total focus on Iraq and Afghanistan, which had to be done, is coming to an end and a new strategic era is dawning," he said.