A senior official at the presidential office has expressed a pessimistic view on applying the example of Libya to the North Korean nuclear issue.

The presidential official told reporters on Friday that it's a personal opinion, but it will be impossible to apply the Libyan example to North Korea.

The official said that the North Korean nuclear issue has been going on for 25 years, and it does not end just by announcing a comprehensive package deal. 

The official added that it would be realistic to take a step-by-step approach in due order to dismantle the nuclear weapons and verify the dismantlement.  

The U.S.' newly appointed national security adviser John Bolton has referred to the case of Libya as a means to denuclearize Pyongyang. 

In 2003, Libya agreed to destroy all of its chemical, nuclear and biological weapons stockpiles in exchange for the normalization of its relations with the U.S. and Europe and the easing of economic sanctions it had been under.