McMaster, a Republican running for governor next year, visited the medium-security brig for 2 1/2 hours and toured the area where other detainees in the war on terror have been held. He came to discuss coordination among federal, state and local law enforcement.
The brig, commissioned 20 years ago, is located about 15 miles from Charleston at the south end of the sprawling Charleston Naval Weapons Station.
"It's the finest brig in the United States. They are hard and tight and they are ready and able to do whatever is asked of them. There is no doubt about that," the state's chief prosecutor said.
McMaster pledged to do whatever was necessary to make sure the state was ready to house any detainees but said he hoped Congress would ensure they are not brought to the U.S.
"Every base in the country is surrounded to some extent by soft civilian targets," McMaster said. "Terrorists as we know will not attack a hardened target. They will attack the surrounding civilian populations. Bringing enemy combatants to our shores is a mistake."
The Obama administration says it wants to shut down the detention center in Guantanamo Bay, Cuba.
The brig has been suggested in media reports as a possible location to house the detainees, though nothing official has been decided.
"Bringing them to Charleston, of course, has a potential for putting people at risk," McMaster said.
South Carolina's U.S. senators differ on whether detainees should be sent to the brig. But Republicans Lindsey Graham and Jim DeMint say they will work together to keep the accused terrorists out of federal courts.
DeMint opposes transferring any detainees to American soil.
Graham has said he is open to trying them at the brig if part of a comprehensive plan to try them in military courts and incarcerate them in other states.
He said the military must both protect the detainees and keep them from escaping.