Speaking in the suburbs of Washington which are home to thousands of defense jobs, Romney blamed Obama for the proposed $1.2 trillion that is set to be cut from Pentagon spending as part of a deal Obama made with Congress in the summer of 2011.

Known as "sequestration," the mandatory cuts in defense and other areas were agreed on by the White House and Republicans in Congress last year in a deal to raise the US debt ceiling.

"It's a strange proposal in the first place, it's even stranger that it's being put in place," Romney told a crowd at the American Legion in Springfield.

The obligatory cuts are due to begin in January if the two parties in Congress cannot agree on budget savings.

"How in the world as commander-in-chief you can stand by as we shrink our military commitment financially is something I don't understand, and I will reverse it," Romney said.

The former Massachusetts governor was speaking only a few miles from the Pentagon in Virginia, a swing state in the Nov. 6 election.

He said that the defense cuts would cost Virginia 136,000 jobs if they go through, and he blasted Obama for what he said was an "unthinkable" cut to America's military strength.

With 40 days until the election and early voting already underway in some key states, Romney took shots at Obama over second-quarter gross domestic product numbers that were revised downward Thursday morning.

The Republican compared Russia's economic growth to that of the United States, which experienced 1.3 percent growth in the second quarter, and said it was evidence that the economy is a national security issue.

"1.3 percent versus Russia at 4 percent. China at 7 to 8 percent," Romney said. "We're at 1.3 percent. This is unacceptable. It is not working," he said.