The turnaround in the U.S. approach to North Korea over the past year has achieved tangible limits on Pyongyang's nuclear capabilities but will not guarantee a final denuclearization in the near future, an American expert told the Nov. 12 symposium.

It is still questionable whether North Korea has made a strategic decision to give up its nuclear deterrent, said Gary Samore, vice president and director of studies at the Council on Foreign Relations.

"From North Korea's standpoint, its nuclear test (in October 2006) forced the United States to back down from its policy of seeking complete and immediate disarmament, and pursue an alternative policy of gradual and incremental disarmament," Samore said.