MT. PLEASANT, S.C. — Republican presidential candidate Mitt Romney stepped aboard a World War II-era aircraft carrier docked here in Charleston Harbor on Thursday to deliver a forceful defense of military spending.

During an era of fiscal austerity in Washington, Romney said he wants to grow the nation’s defense budget to help fund an expansion of the country’s aging Navy and Air Force fleets. Romney said he would like non-combat defense spending to rise from 3.8 percent of gross domestic product to 4 percent.

“People say to me, ‘Well, gosh, Mitt, isn’t there a lot of waste in the Department of Defense?’” Romney said. He acknowledged that there was, but added: “With those savings, I don’t want to take those dollars and send them out to social programs as the Europeans have done, shrinking their military year after year after year.”

Instead, Romney said, he would commission new ships and aircraft, as well as grow the ranks of active duty personnel by about 100,000.

“We all recognize that America needs to economize, but I don’t believe that we can economize on securing our nation and protecting our citizens and ensuring that the world remains safe and free for us and for our children,” said Romney, a former Massachusetts governor and businessman.

Romney gave a 15-minute address before a few dozen veterans on board the USS Yorktown, which has been decommissioned and is now a floating museum. He is not the first White House aspirant to use the ship as a backdrop. Another Massachusetts politician, Sen. John Kerry (D), officially launched his 2004 presidential campaign with a speech in front of the USS Yorktown.

In his remarks, Romney cited Defense Secretary Leon Panetta by name, saying he disagreed with the Obama administration’s proposals to trim defense spending. He criticized Obama, too, calling him part of a “class of permanent politicians” whose policies are slowing down the economy.

“The real reason that maybe we’re not running as fast as we have in the past is that we’re having to carry him on our shoulders — and he and government have gotten a little heavy,” Romney said.

Romney added: “With a heavier and heavier hand, government places its will on free people and free institutions, and so we have an economy that’s struggling. Instead of being free of the burden of government, it’s overwhelmed with taxation and regulation — with policies that don’t make America as competitive globally as we can be.”

Romney, who is the national front-runner for the GOP presidential nomination, is in South Carolina for two days of defense and foreign policy-themed events. Earlier Thursday, he announced his team of foreign policy and national security advisers, which includes an array of high-profile Bush administration officials. On Friday morning, he will deliver a major foreign policy address at the Citadel.

Many of those in attendance for his speech here Thursday rushed up afterwards to shake Romney’s hand. One woman told him he had delivered “a wonderful patriotic speech.” Making an apparent contrast with Obama, she added: “It means so much to hear somebody loves America.”

“I sure do,” Romney replied. “From the tip of my head to the bottom of my toes.”

One man bestowed on Romney perhaps the greatest compliment any of the Republican presidential hopefuls could hear.

“My wife taught school for 25 years,” he said. “She’s a Ronald Reagan fan. She says you’re the next!”

“Thanks so much,” Romney said. “Give her my best, will you?”