North Korea claims its subsea drones could trigger ‘radioactive tsunamis’

North Korea's new Unmanned Underwater Nuclear Attack Craft Haeil drone is said to be able to generate giant "radioactive tsunamis" to attack enemy targets.  

The drone is built to “stealthily infiltrate into operational waters and make a super-scale radioactive tsunami through an underwater explosion" to destroy enemy naval strike groups and ports, state news agency Korean Central News Agency (KCNW) has reported. 

The device was tested in the waters off South Hamgyong province on Tuesday (21 March), and it cruised for over 59 hours at between 80 to 150 metres deep before being detonated, according to the agency. 

The test "verified [the drone's] reliability" and "confirmed its lethal strike capability", KCNA said.

The test of the  “nuclear underwater attack drone” was part of a three-day exercise that included cruise missile launches and simulated nuclear attacks on unspecified South Korean targets.

The country's leader, Kim Jong Un, said he was "greatly satisfied" with the results. He added that the test should serve as a warning for the US and South Korea to "realise the DPRK's unlimited nuclear war deterrence capability being bolstered up at a greater speed", AFP reported.

Analysts have raised concerns over the veracity of North Korea's claims regarding the "secret weapon", but that hasn't stopped international tensions from rising.  

"Pyongyang's latest claim to have a nuclear-capable underwater drone should be met with scepticism," said Leif-Eric Easley, a professor at Ewha University in Seoul. "But it is clearly intended to show that the Kim regime has so many different means of nuclear attack that any pre-emptive or decapitation strike against it would fail disastrously."

The day before the news of the drones were made public, the US and South Korea concluded the largest joint field exercises in five years, and the two nations are currently preparing a new round of joint naval drills.

During a ceremony marking West Sea Defence Day - an annual holiday to commemorate the soldiers who died while defending the maritime border between the Koreas - that same week, South Korea's President Yoon Suk-yeol said he would make sure North Korea "pays the price for its reckless provocations".

North Korea, in turn, described the exercises as "intentional, persistent and provocative war drills" and said they had pushed it to "an irreversibly dangerous point".

The North Korean drone is named 'Haeil', a Korean word meaning tidal waves or tsunamis. The KCNA said the drone has been in development since 2012 and has been tested more 50 times in the past two years, although it has never been mentioned before today in state media. 

Kim Dong-yub, a professor at Seoul’s University of North Korean Studies, said it is impossible to verify North Korea’s claims about the drone’s capabilities. But, he said, the tests intend to communicate that the weapon has enough range to reach all South Korean ports.

“This uncrewed underwater vehicle will be vulnerable to anti-submarine warfare capabilities if it were to deploy beyond North Korea’s coastal waters. It will also be susceptible to preemptive strikes when in port,” said Ankit Panda, a senior analyst at the Carnegie Endowment for International Peace.

North Korea is believed to have dozens of nuclear warheads. However, there are different estimates about the levels to which the country would be able to engineer those warheads to fit on the new weapons.

South Korean Defence Minister Lee Jong-Sup said the North probably hasn’t yet mastered the technology to place nuclear arms on its most advanced weapons, but acknowledged the country was making “significant progress.”

In 2023 alone, North Korea has fired more than 20 ballistic and cruise missiles to date, following a record of more than 70 fired last year.