American Morning

South Carolina governor admits extramarital affair

Update, 2:44 p.m.

(CNN) - South Carolina Gov. Mark Sanford, just back from a secret trip to Argentina unknown to his staff or his wife, admitted Wednesday he has carried on an extramarital affair.

"I've been unfaithful to my wife," Sanford told a news conference in Columbia, the state capital. "I developed a relationship with what started as a dear, dear friend from Argentina." His voice choking at times, Sanford apologized to his wife and four sons, his staff and supporters, and said he would resign immediately as head of the Republican Governors Association.

The affair was discovered five months ago, Sanford said.

(CNN)- Gov. Mark Sanford is set return to his office Wednesday following widespread confusion over his whereabouts, a spokesman for the South Carolina Republican said.

Earlier: South Carolina Gov. goes missing

Joel Sawyer, Sanford's communication's director, also said in a statement Tuesday the governor called his chief of staff Tuesday morning and was "somewhat taken aback by all of the interest this trip has gotten."

"Given the circumstances and the attention this has garnered, the governor communicated to us that he plans on returning to the office tomorrow," Sawyer said in the statement.

Full statement:

Governor Sanford called to check in with his Chief of Staff this morning. It would be fair to say the governor was somewhat taken aback by all of the interest this trip has gotten. Given the circumstances and the attention this has garnered, the governor communicated to us that he plans on returning to the office tomorrow.

CNN's Jason Carroll takes a look at the governor's five day hike.