WASHINGTON -- The Pentagon has asked Congress to revise its current spending plan to include $800 million for new, bomb-resistant vehicles.

Defense Secretary Robert M. Gates asked Congress for approval to transfer nearly $1.2 billion to the Mine Resistant Ambush Protected vehicle program to get an estimated 3,500 of the vehicles to Iraq by year's end, defense officials said.

The funds, to be added to almost $4 billion already programmed for MRAPs this year, will speed up the timetable for getting deployed troops the best armored vehicles possible, said John Young, director of defense research and engineering and chairman of the Defense Department's MRAP task force.

By reprogramming an additional $1.2 billion to the program, the department can sign contracts for an additional 2,650 MRAPs, Young told Pentagon reporters today. This will bring the department's total MRAP order to 6,415.

Nearly three-quarters of those MRAPs are slated for delivery by Dec. 31. "By the end of the year, we hope to have delivered 3,935 vehicles," Gates said.

Congress is expected to approve the request.

MRAP maker Force Protection Industries reported that its factory in Charleston, S.C., is hiring dozens of new employees every week to churn out the vehicles "as fast as humanly possible."

Another MRAP manufacturer, General Dynamics Land Systems, announced that it had delivered its first MRAPs to the Marine Corps less than 120 days after getting its first production order.

"The companies that have been awarded the contracts are ramping up their production capabilities," Gates said in late June. "I am pressing them very hard to see where they can cut the time scale as well as increase their production."

The vehicles are not perfectly safe, but they're an improvement over Humvees, Gates said.

"These large IEDs can destroy an Abrams tank," he said. "There is no sure-fire guarantee that anything will provide absolute protection against these. But I think the experience of the Marines in Anbar suggests that the MRAP, and particularly with the V-shaped hull, does provide significantly enhanced protection for the soldiers and Marines inside."