A South Korean expert has said there is a strong possibility North Korea may carry out its sixth nuclear test in the near future.

Lee Chun-geun, a senior researcher at the Science and Technology Policy Institute, spoke at a forum on Korean unification hosted by the Institute for Peace Affairs on Friday.

Lee said that North Korea could soon conduct an even stronger nuclear detonation, citing the technological demand and room for improvement which he said is relatively certain.

He said that despite the North's five nuclear tests so far, it still can't be said that there has been sufficient standardization.

Lee said that even if Pyongyang mass-produces and deploys one or two different types of standard warheads due to urgent military need, the regime will need to carry out more tests to improve and optimize them.