During a 2009 visit to Pyongyang to seek the release of two detained American journalists, former U.S. President Bill Clinton raised the issue of abducted Japanese nationals with then-leader Kim Jong Il, a hacked document released by the secret-spilling site WikiLeaks has shown.

The memo, attached to an email sent to John Podesta, a former Clinton White House chief of staff who joined the ex-president on his mission, is part of a trove of emails released by WikiLeaks.

Podesta, head of the liberal Center for American Progress think tank at the time, now serves as the campaign chair for Democratic U.S. presidential nominee Hillary Clinton's White House bid. WikiLeaks has been publishing emails since Oct. 7 from Podesta's account, which experts say was targeted by Russian hackers.