The Pentagon's military and civilian chiefs on Wednesday defended the department's proposed defense budget for the 2012 fiscal year, warning of "tragic consequences" if Congress cuts deeply into military spending.

Mike Mullen, U.S. chairman of the Joint Chiefs of Staff, together with Defense Secretary Robert Gates, justified the new budget proposal before the House of Representatives Armed Services Committee.

"We shrink from our global security responsibilities at our peril," said Gates. "Retrenchment brought about by short-sighted cuts could well lead to costlier and more tragic consequences later -- indeed as they always have in the past."

In the budget for FY 2012 that begins Oct. 1, the Pentagon asked for 553.1 billion dollars for its "base" defense budget which excludes the cost of the wars in Iraq and Afghanistan. This represents an increase of 4.2 billion dollars from the level the department requested for this year.

The Pentagon also asked for 117.8 billion dollars to fund the wars in Iraq and Afghanistan, 41.5 billion dollars below its request for this year.

As President Barack Obama's federal budget for the current fiscal year which started last October has never been enacted by Congress, the Pentagon is now operating under a stop-gap funding measure due to expire on March 4.

The Pentagon requested 549 billion dollars in "base" defense budget for this year, and the stop-gap measure, formally known as continuing resolution, would provide 526 billion dollars, a cut of 23 billion dollars.

"I want to make clear that we face a crisis on our doorstep if the Department of Defense ends up with a year-long continuing resolution or a significant fund cut," said the secretary.

Mullen warned there is "real danger" if Congress fails to pass this year's defense budget. He also voiced opposition to cuts to military aid or assistance to countries like Egypt.