The mission took root in early July after one of the reporters told relatives in a phone call that North Korea would grant them amnesty in exchange for a visit from Clinton, according to a senior Obama administration official cited by CNN.

President Barack Obama said Wednesday that he was 'extraordinarily relieved' that the journalists returned home safely.

'The reunion that we've all seen on television, I think, is a source of happiness not only for the families but for the entire country,' Obama said before boarding Marine One for a trip to Elkhart, Indiana.

He thanked Clinton and former vice president Al Gore for their 'extraordinary work' toward the release of Lee and Ling.

Obama said he spoke with Clinton as well as the families of the journalists.

The former president will brief members of the White House's national security team on his trip soon, according to administration spokesman Robert Gibbs.

'We are very pleased with the outcome, and I'm hopeful that the families are going to be able to get some good time together in the next few days,' Obama said.