The governor said he "never crossed the ultimate line" with anyone but Maria Belen Chapur, the Argentine at the center of a scandal that has derailed his once-promising political career.
"This was a whole lot more than a simple affair, this was a love story," Sanford said. "A forbidden one, a tragic one, but a love story at the end of the day."
During an emotional interview at his Statehouse office with The Associated Press on Tuesday, Sanford said Chapur is his soul mate but he's trying to fall back in love with his wife.
"And so if you end up 50 years here on Earth and you know, alright, maybe I get another 30 and if you come into connection with a soul that touches yours in a way that no one's ever has, even if it's a place you can't go, this notion of knowing that you know, for me, became very important."
He said that during the encounters with other women he "let his guard down" with some physical contact but "didn't cross the sex line." He wouldn't go into detail.
Sanford, 49, said the casual encounters happened outside the U.S. while he was married but before he met Chapur, on trips to "blow off steam" with male friends.
Sanford also admitted, including what was to be a farewell meeting in New York chaperoned by a spiritual adviser soon after his wife found out about the affair.
After that disclosure, South Carolina Attorney General Henry McMaster said Tuesday he has asked the State Law Enforcement Division to review all of Sanford's travel records to see if any laws have been broken.
Sanford described five meetings with Chapur over the past year, including two romantic, multi-night stays with her in New York before they met there again intending to break up.
He said he saw her two other times, including their first meeting in 2001 at an open-air dance spot in Uruguay.
"There was some kind of connection from the very beginning," he told The Associated Press, though he said neither that meeting nor a 2004 coffee date in New York during the Republican National Convention were romantic. Sanford had been considered a potential 2012 presidential contender before the scandal broke last week.
His interview was the first disclosure of any liaisons with Chapur in the United States and contradicted a public confession last week during which he admitted to a total of five encounters over their eight-year relationship.
He previously announced he would reimburse the state for money spent during a government trip to Brazil and Argentina in June 2008 when he saw Chapur. It was then, he said, that their relationship became physical, and the e-mails they'd exchanged for years reflected their anguish over what they had done.
"Now I am frightened," he told the AP, describing his state of mind at the time. "It was before safe. But now it's not safe. We gotta put the genie back in the bottle."
He insists no public money was used for any other meetings with her.
He saw Chapur again in mid-June of this year, visiting Argentina without telling his staff he was going to be out of the country. He instead led them to believe he was hiking on the Appalachian Trail.
By the time he returned to a puzzled public, staff and family, his public image and emotional state had unraveled. He admitted the affair at a rambling press conference.
Now Sanford is attempting to salvage his personal and professional lives. He and wife Jenny, parents of four sons, say they are trying to reconcile their 20-year marriage but have not been sharing the same house for several weeks. Jenny Sanford found out about the relationship in January when she discovered a letter the governor had written to his mistress.
She did not immediately return a message seeking comment Tuesday, but she told The Associated Press in an interview Friday that her husband had repeatedly sought permission to visit Chapur.
"I said absolutely not. It's one thing to forgive adultery; it's another thing to condone it," she said.
The governor said he met Chapur in Punta Del Este, Uruguay, in 2001 after his final term in Congress and before his first term as governor. He said the two struck up an e-mail correspondence after meeting on a dance floor - a chance encounter during which he counseled her into the night about her failing marriage.
For the next seven-plus years, Sanford said, the two exchanged messages, sometimes sporadically.
They met in New York two more times in 2008: two nights in Manhattan in September and three nights in the Hamptons in November. Each time, Sanford claims he flew coach, paid for it himself, paid for the hotels in cash and told his staff he was reachable by cell phone.
"At that point I was very careful, everything was paid for in cash," Sanford said. "And you won't find a credit card record."
In early 2009, after Jenny Sanford discovered the affair, the couple went into counseling. She has told The Associated Press that he asked her several times to visit the mistress and she refused.
But the governor claims he wanted to end the affair in person and, with his wife's permission, went to New York with a "trusted spiritual adviser" serving as chaperone. The three went to church and dinner together and parted ways the same night.
But he visited Chapur again in Argentina on June 18, the trip that brought the whole affair to light.
Sanford told AP that has some life questions to ponder: "If I personally end up with some life questions that I need to get answered in my own way so that when I meet my maker and when I'm in that last dying breath, and I weigh the costs and say, to me and everybody's got their own value system, but to me, even if it's a place I could never go, if I wanted to know that I knew that I knew, if that's more important to me than running for president, that's my prerogative as a human being."