An analyst from a state-run think tank said North Korea likely possesses up to 150 nuclear weapons and may increase its stock to more than 200 by 2030, and 400 by 2040.

At a forum hosted by the Korea Institute for Defense Analyses on Wednesday, Lee Sang-kyu, chief of the institute's nuclear security research division, said the North is expanding facilities to enhance its nuclear production capabilities.

According to the KIDA expert's analysis, the North has 115 to 131 uranium-based weapons and between 15 and 19 plutonium bombs, with a nuclear arsenal of 127 to 150.

The projection is two to three times higher than the approximately 50 estimated by overseas research institutes.

Referring to the North's enhanced uranium enrichment capabilities, Lee said its nuclear weapons stock may rise to 243 by 2030 and 429 by 2040.

The analyst also said that Russia may provide the North with the technology, materials, parts and skills to design and build a five-thousand to six-thousand-ton-class submarine.

He added, however, that it would likely take at least ten years for the regime to develop a small reactor for the nuclear-powered submarine it plans to build.