Thae Yong-ho, former North Korean ambassador to Britain, said that the North would not disarm nuclear weapons in full.
Thae Yong-ho's statement, which is also a North Korean defector, was presented ahead of the North Korea-US summit which brought together Chairman Kim Jong-un and Donald Trump's President in Singapore on June 12.
According to Thae Yong-ho, talks between the two countries will not end 'sincerely with the disarmament of all nuclear weapons' but only 'reduce the ability of North Korea's nuclear threat'.
"Ultimately North Korea will remain a nuclear power even though it is considered a non-nuclear country," ThaeYong-ho said, as reported by the Channel News Asia page on Monday (14/5).
At a meeting of two Koreas last month the two countries committed to achieve denuclearization on the Korean Peninsula. Pyongyang two days ago also announced it will destroy its nuclear test site next week.
Washington wants North Korea to completely destroy its nuclear weapons and stressed that the terms will be key to negotiations.
Pyongyang says they do not need nuclear weapons if their security is assured.
But Thae Yong-ho, one of North Korea's top defected officials, said: "They (North Korea) will argue that the denuclearization process will make their country lose and they will refuse nuclear disarmament."
In writing in his memoirs, Thae Yong-ho also said, "People should know North Korea is very dependent on their nuclear program more than anything."