North Korea may conduct a nuclear test within a short period of time, using the number three tunnel at the Punggye-ri nuclear facility, if leader Kim Jong-un gives the green light.

The Defense Intelligence Agency shared the assessment on Wednesday during a closed-door parliamentary audit, according to ruling Democratic Party(DP) Rep. Park Sun-won, vice chair on the National Assembly's Intelligence Committee.

The agency reported that the North is attempting to expand the capacity of its uranium enrichment facilities, including its main Yongbyon nuclear complex, and establish the infrastructure to produce various types and amounts of nuclear warheads.

The agency said Pyongyang is focused on developing a variety of missiles and military spy satellites and that it appears to have secured intercontinental ballistic missile technology with a range surpassing 13-thousand kilometers, making it capable of reaching the U.S. mainland.

According to main opposition People Power Party(PPP) Rep. Lee Seong-kweun, vice chair on the committee, the agency said a trial operation of the North's improved Romeo-class submarine is underway following its launch in September 2023.

Since Kim ordered the regime to construct two large warships each year, the agency has detected the launch of one vessel in April and another in June this year, reporting that the actions are part of the North's push to secure maritime operational capability.