Sen. John McCain criticized President Barack Obama’s newly unveiled strategy for a leaner and more flexible military, saying it portrays the United States as “weak and withdrawn.”

“I understand these savings have to be made, but I’m more worried about the perception in the world about what the United States is doing,” the Arizona Republican said during an appearance today on CBS’ “Face the Nation.”

McCain, who is ranking member of the Senate Armed Services Committee, warned that the forward-looking military plan neglects the possibilities of unrest in Iraq and more ground wars that require a large force.

Top defense officials appearing on the same show backed the administration’s military policy and pointed out that it stems from budget cuts demanded by Congress.

“Clearly, we face the constriction of having to reduce the budget by almost a half a trillion dollars,” Defense Secretary Leon Panetta said. “The issue we had to face is: Do we do this by simply cutting across the board as we’ve done in the past in this country and created a hollow force? Or do we develop a strategy as to exactly the kind of force we need for the future?”

Panetta praised the plan he joined Obama in unveiling last week.

“The bottom line is, when we face an aggressor, anyplace in this world, we’re going to be able to respond and defeat them,” Panetta said.

Martin Dempsey, chairman of the Joint Chiefs of Staff, joined Panetta on the show and acknowledged concerns about whether a slimmer military could handle two ground wars at once, as it has had to do for the past decade in Iraq and Afghanistan. But Dempsey said the new strategy aims to build a force “that is capable of doing more than one thing at a time.”

“We’ve learned an enormous amount over the last 10 years about how to wage war, and it’s not just in the traditional ways,” he said.

Dempsey appeared to share some of McCain’s concerns about the perception that the downsizing could create, but he dismissed the idea that the United States is backing down from its military might.

“What worries me is that, because of the conversation that we’re having this year about changing strategy and budget problems, there may be some around the world who see us as a nation in decline, and worse, as a military in decline, and nothing could be further from the truth,” Dempsey said.