a rare appearance at the Pentagon, he unveiled a far-reaching defence review under which thousands of troops are expected to be axed.
"So yes, our military will be leaner," Mr Obama told reporters on Thursday, "but the world must know - the United States is going to maintain our military superiority with armed forces that are agile, flexible and ready for the full range of contingencies and threats."

Joined by Defence Secretary Leon Panetta, President Obama stressed that the defence budget would still grow, but at a slower pace.

He said the US was "turning the page on a decade of war" and faced a "moment of transition".

"Even as our troops continue to fight in Afghanistan, the tide of war is receding," he said.

President Obama added: "At the same time, we have to renew our economic strength here at home, which is the foundation of our strength around the world. That includes putting our fiscal house in order."

The president said the new strategy would end "long-term, nation-building with large military footprints", with the Pentagon instead pursuing a national security strategy based on "smaller conventional ground forces".

Mr Panetta said the review would make the US military "more agile, more flexible, ready to deploy quickly".

Mr Obama has been closely involved with shaping the blueprint, meeting high-ranking defence officials six times since September.