North Korea said on Saturday it has successfully conducted an underwater test-fire of a submarine-launched ballistic missile, which, if true, would indicate progress in the secretive state's pursuit of building missile-equipped submarines. The North's leader Kim Jong Un oversaw the test-launch from a location off-shore as the submarine dove under water and 'a ballistic missile surfaced from the sea and soared into the air, leaving a fiery trail of blaze,' the official KCNA news agency said. 'Through the test, it was verified and confirmed that the underwater ballistic missile launch from a strategic submarine fully achieved the latest military, scientific and technical requirements,' KCNA said. North Korea is under United Nations sanctions banning it from developing or using ballistic missile technology.