North Korea recently revealed it was building a nuclear-powered submarine for the first time. However, experts believe Pyongyang faces overwhelming technical challenges that make its nuclear submarine ambitions nearly impossible.

The submarine could significantly escalate security concerns on the Korean peninsula and in the Taiwan Strait, experts say North Korea's construction of a nuclear-powered submarine could significantly escalate security concerns on the peninsula and in the Taiwan Strait,

North Korea has conducted a slew of underwater-launched ballistic missile tests since 2016, but all launches were made from the same 2,000-tonne-class submarine which has a single launch tube. Many experts call it a test platform, rather than an operational submarine in active service.

North Korean leader Kim Jong Un inspected a project to build a nuclear-powered submarine, state media reported Saturday, saying that "radically" boosting the navy was a key part of Pyongyang's

Last week's accidental shelling of a South Korean village occurred less than 20 miles from the border of the nuclear-armed North.