Relations between the US and Northern Korea seems to be improving. USA removed N. Korea from the list of terrorism-supporting states when they agreed upon the control over the Pyongyang nuclear program.
Let's remember that, in 2007, the Northern Korea has ceased the work on the nuclear reactor in exchange for smoothing sanctions and receiving aids.
The Northern Korea was introduced in the list of countries that support terrorism by the USA in 1998. Currently the list includes Cuba, Iran, Sudan and Syria.