Looks like he has done it before:
http://www.pbs.org/newshour/bb/asia/july-dec05/nkorea_10-24.html
Excerpt:
NORTH KOREA'S NUCLEAR PROGRAM
October 24, 2005
Bill Richardson
New Mexico Gov. Bill Richardson, who recently returned to the United States from an unofficial visit to Pyongyang, discusses the North Korea's pledge on Monday to continue with six-party negotiations over its nuclear weapons program.
So how's that pledge thingy working out for Lil Kim? Did he keep his word?