For the first time, North Korean leader Kim Jong-un revealed his country’s nuclear warhead in person alongside a system meant to manage such operations, saying the regime needs an “exponentially bigger” nuclear arsenal amid potential preparations for a nuclear test.

The North’s official Korea Central News Agency said Tuesday that on the previous day, Kim inspected new tactical nuclear weapons as well as technologies needed to make compatible all weaponry, including nuclear warheads. The KCNA released a photo of the Hwasan-31, its first nuclear warhead ever made public, saying Kim also tested the reliability of a nuclear management system during last week’s exercises.

They involved chiefly an underwater drone capable of nuclear attacks on South Korea and the United States. The drone was tested for the second time on Monday, the KCNA added, referring to the new weapon it claims can deliver sneak attacks leaving behind a “radioactive tsunami.” The same day, the North simulated nuclear attacks using two short-range ballistic missiles, defying United Nations sanctions that ban ballistic missile launches.

The Tuesday announcement is the latest highlight of an impasse in ties as North Korea makes nuclear threats in response to annual military exercises by South Korea and the US. The routine -- a “rehearsal for invasion” to Pyongyang but a “test for readiness” to Seoul and Washington -- was revived after a five-year hiatus. The efforts yielded no headway on denuclearization, because of differences over whether to seek sanctions relief or disarmament first.

Analysts warn that South Korea and the US are far from reengaging North Korea, let alone resuming nuclear dialogue stalled over “irreconcilable differences.” Shin Jong-woo, a senior analyst at the Korea Defense and Security Forum, suggested that North Korea is closer to another nuclear test, a step that would only complicate peace efforts by the allies.

“The fact that North Koreans displayed the Hwasan-31 warhead means that a nuclear test is imminent,” Shin said, singling out the warhead he said will be used at the test. North Korea last conducted a nuclear test in 2017 and has since faced harsher international sanctions.

Cheong Seong-chang, director of the Department of Reunification Strategy Studies at the Sejong Institute, agrees with Shin, but has reservations over the exact test date and the course of action Kim would pursue after what could potentially become a “moment of reckoning” for Seoul and Washington.

“For Pyongyang, it will double down on nuclear threats, at least in the months leading up to mid-April or late July,” Cheong said, referring to April 15 and July 27. North Koreans celebrate the birth of late founder Kim Il-Sung on what they call the “Day of the Sun” in April, while they less enthusiastically mark the July celebration, meant to commemorate the 1950-53 Korean War truce.

But some experts said South Korea should be more alarmed by North Korea’s rapid nuclear buildup itself than the fact that it could carry out another nuclear test, according to Kim Dong-yub, a professor at the University of North Korean Studies in Seoul.

“North Koreans now can mount multiple nuclear warheads on any weapon of their choice -- be it missiles or underwater drones. And we are potentially underprepared to deal with all that. Isn’t that more frightening than a test we now know means little? We’ve just seen their latest nuclear weapons.” Kim said.

The Defense Ministry in Seoul openly dismissed Pyongyang’s latest undersea drones, saying they may not be as lethal and sophisticated as North Korea claims.

“The South Korean and US intelligence authorities believe that the weapons are still in the early stages of development, and that their effectiveness could be overblown,” the ministry’s spokesperson said Tuesday at a briefing. The ministry, however, did not reveal any details over how exactly the two allies arrived at such a conclusion.