From NBC's Mark Murray and Domenico Montanaro
Fighting back tears at a news conference he assembled, South Carolina Gov. Mark Sanford (R) admitted that he had an affair with a woman living in Argentina. "I have been unfaithful to my wife," he said. "I hurt you all. I hurt my wife. I hurt my boys. And all I can say is I apologize."
Sanford also announced he was resigning his position as chairman of the Republican Governors Association.
The governor's stunning revelation caps a three-day media frenzy, in which it was first reported that the governor was missing; then his staff said he had been hiking the Appalachian Trail; and this morning, the State newspaper discovered he had been in Argentina.
Video: South Carolina Gov. Mark Sanford holds a news conference to explain his absence from the state, and admits he's been having an affair with an Argentinean woman.
In the news conference, Sanford revealed that the affair began about a year ago, that he's seen the woman three times since it began, and that his wife and family found out about it five months ago. Sanford said he and the woman exchanged e-mails and the relationship began as a "casual" friendship. He seemed to suggest that his reason for traveling to Argentina was to end the extramarital affair. He said he spent five days "crying" there, so "repeat it when I came back here."
He also said he told his staff that the Appalachian Trail where he was thinking about going.
Sanford apologized to a myriad of people, including his wife, four sons, friends and the state of South Carolina. He asked for forgiveness, but said he understood that would not come easily.
"I'm committed to trying to get my heart right," he said.