"If my freedom can be good for something, I hope it helps achieve the freedom of all the other hostages," she said.
The Farc has been kidnapping people for ransom and political leverage as part of its 44-year war against the state.
Alvaro Uribe, Colombia's president, is to join Betancourt in her tour through several South American countries, including Ecuador, Brazil, and Venezuela, to discuss the ongoing problem of hostage-taking on the continent.
Betancourt was chained up in jungle camps, her health often in peril, until Colombian security forces duped rebels into handing her and 14 other captives over in a daring rescue operation.
She has lived in Europe since her rescue and says she does not wish to return to politics in Colombia.