The Republican governor told "Fox & Friends" he pledges to put the law, which is awaiting debate in the Senate after passing in the House, into effect as soon as possible.
"Well, I'll sign it immediately and it will go into effect," McMaster said. "The momentum is moving towards protecting life and South Carolina is a very pro-life state."
McMaster's comments come as Alabama passed the most restrictive abortion ban in the country, putting a hard stop at six weeks and with no exceptions for rape and incest. Other states that have passed similar bills include Kentucky, Mississippi, Ohio, and Georgia.
The South Carolina leader said that the state will allow for some exceptions and the main point of the bill is that once a heartbeat is detected -- which can be as early as six weeks -- abortion is illegal. The state currently bans abortions after 20 weeks of gestation.
"You got to draw the line somewhere," he added. "There are a lot of people that say you are a person at conception."
"Life is precious," McMaster said, "and we must protect it."