The DPRK-U.S. Agreed Framework signed in 1994 calls on the U.S. to build two LWRs and provide them to the DPRK on a turn-key basis by 2003.

Had the U.S. kept the above-said promise, the nuclear issue on the Korean Peninsula would have not remained so complicated as now.
It is universally recognized right of the countries both inside and outside the NPT to exercise the above-said right to use nuclear energy for peaceful purposes. It is entirely just for the DPRK to exercise this legitimate right.