President Obama said Wednesday he wants to cut an additional $400 billion in defense spending as part of an overall plan to trim the federal deficit – a move that some experts say will significantly reduce Pentagon muscle and capability.

Obama did not specify how the defense cuts were to be made but said he would work with Defense Secretary Robert Gates and Joint Chiefs Chairman Adm. Mike Mullen to “identify waste and improve efficiency and effectiveness.” He said he would not make specific decisions until after the Gates-Mullen review is complete.

The announcement came during a speech at George Washington University in which the president outlined a plan to trim some $4 trillion from the nation’s mounting $14 trillion debt over the next 12 years.

Obama acknowledged the Defense Department’s recent spending initiatives that have trimmed more than $400 billion over the last two years.

“And I believe we can do that again,” he noted, calling for a “fundamental review of America’s missions, capabilities and role in a changing world.”

Although the president did not offer a specific timeframe for the review and resulting cuts, Pentagon officials said the new initiative likely would impact the Defense Department beginning with the fiscal year 2013 budget.

In a press conference following the president’s speech, Pentagon spokesman Geoff Morrell confirmed that defense officials would work to find additional savings.

“Secretary Gates believes that the Department of Defense cannot be exempt from efforts to bring federal deficit spending under control,” Morrell is quoted in a press release issued by the Pentagon. “However, it is important that any reduction in funding be shaped by strategy and policy choices and not by a budget math exercise.”

He conceded that additional cuts would come at the expense of military muscle.

“The secretary has been clear that further significant defense cuts cannot be accomplished without reducing force structure and capabilities,” Morrell noted. “The comprehensive review of missions, capabilities and America’s role in the world will identify alternatives for the president’s consideration.”

He added that accomplishing the president’s cost-cutting objectives “must be about managing risks associated with future threats and national security challenges and identifying missions that the country is willing to forego.”

Retired Air Force Maj. Gen. Rick Goddard said the Defense Department is not immune to the current budget crisis.

“Every department of the government must help fix the problem,” he stressed during a Thursday morning interview. “We have a responsibility to be efficient and protective of the tax dollar. But the Defense Department finished cutting fat a long time ago.”

The former Warner Robins Air Logistics Center commander and currently a consultant to the 21st Century Partnership said savings of the magnitude requested by the president would indeed require cutting into military muscle.

“People are the most expensive piece,” he conceded. “You would have to cancel programs like the F-35, cut back the number of people dramatically or some combination of the two.”

Old weapons systems would also be scrutinized and assessed. “And that would come at a time when you can’t afford to squander that capability because you’re not replacing them with anything new,” Goddard emphasized. “The idea that we would have to cut muscle is exactly right … and we would do so while we’re engaged on three fronts.”

Goddard said the proposed cuts would place even greater pressure on logistics centers to work more efficiently and use every manpower position to produce more at less cost.

“It’s going to be incumbent on every government employee – including those at our depots – to be as efficient as possible,” he said. “They need to work side by side with one major focus and that’s to get weapon systems back to the users as quickly and efficiently as possible.”