North Korea claimed today to have tested a nuclear-capable underwater done designed to generate gigantic “radioactive tsunami” that would destroy naval strike groups and posts. Analysts believe that the device may pose major threat as it underlines North’s commitment to raising nuclear threats for the world.

Kim Jong Un-lead North Korea cruised the drone underwater at a depth of 80 to 150 meters (260-500 ft) for over 59 hours during the test. It detonated in the waters off North Korea’s east coast. The drone system has been called ‘Haeil’ or tsunami that cand estroy naval stricker groups and major ports by creating a super-scale radioactive wave through an underwater explosion.

These tests come after South Korea and US launched their largest amphibious landing drills in years on Monday. The US ship, USS Makin Island docked at a naval base in South Korea;s southeastern port city of Busan earlier this week.

These tests are also a result of South Korean President Yoon Suk Yeol’s pledge to make North Korea pay for its reckless provocations as he attended a remembrance service honoring 55 South Korean troops killed during major clashes with the North.