North Korea is still working on improving missiles, but its latest submarine-launched ballistic missile tested Tuesday is still an early-stage weapon that can be intercepted, Defense Minister Suh Wook told the National Defense Committee on Thursday.

“We have to look at not just that single missile launch but a whole system that goes with it,” Suh said during an annual National Assembly audit, referring to North Korea’s capability to build a submarine big enough to fire multiple SLBMs.

North Korea used a small submarine that could fire a single SLBM to carry out the test, according to the military, which believes Pyongyang still does not have the resources to launch a full SLBM strike.

Park Jong-seung, head of the Agency for Defense Development, backed Suh, saying North Korea would need a submarine bigger than the 2,000-ton vessel it used after modifying it at the last minute to complement the missile.

It would take at least five years for North Korea to match South Korea’s SLBM technology, according to the chief of the country’s weapons developer. Seoul conducted its first SLBM test using a 3,000-ton homegrown submarine, becoming the first non-nuclear state to have developed the technology.

Meanwhile, Suh said he will ask the appeals court to look at a case involving the death of the country’s first openly transgender soldier who was forcibly discharged after she received sex reassignment surgery.

Two weeks ago, a court ruled in favor of Byun Hee-soo, the former staff sergeant who was dismissed from the Army, which had found her mentally and physically unfit to serve after a gender reassignment operation. She filed a lawsuit to challenge the decision, but died by suicide in March this year.

“We will not avoid dealing with issues surrounding the case,” Suh said of mounting criticisms that the military should have held open debate on dealing with transgender soldiers, as he promised shortly after Byun’s death in March. No discussions have since taken place.

The military, which bans transgender people from serving but has no rules on individuals who have gender affirmation surgery after joining, said it will start the debate by December as it prepares for the appeals, which the Army will handle as lead counsel.

But the Justice Ministry can ask the Army to drop the appeals. The justice minister said he will get second opinions from an appeals committee he intends to set up soon to make the decision.

Byun’s attorney said the Army should accept the ruling. The court ruled that Byun was a woman and the military should have used standards applied to women, not men, to determine her fitness. The court said that the government and the Assembly should introduce rules to handle transgender soldiers, like Byun.