LONDON — South Africa’s president said Wednesday that his corruption-ridden party, the African National Congress, had lost its founding values and now faced a “Damascus moment” in trying to regain the people’s confidence and support.

“We have said to ourselves: ‘We cannot carry on like this. We have deviated from the values and the principles that have always defined the A.N.C.,’” President Cyril Ramaphosa said in an interview with The New York Times in Davos, Switzerland, where he was attending the World Economic Forum.

“People have lost confidence in us,” said Mr. Ramaphosa, who will lead his party in national elections that will most likely be held in May.

Repeating the message he was pushing at the forum, Mr. Ramaphosa said efforts to clean up the African National Congress were already underway. And he pledged to return the party of Nelson Mandela to its past glory.