AP Seoul

North Korea said it has repaired its damaged second naval destroyer and launched the ship into the water in the presence of leader Kim Jong Un, about three weeks after it capsized during a botched launch ceremony.

In a lavish ceremony on Thursday, Kim boarded the warship and told troops that nothing can block his country's push to bolster its naval combat power in the face of US-led hostilities, the Korean Central News Agency said on Friday. 

The country's extremely secretive nature makes it virtually impossible to independently confirm the announcement on the ship's repair. Outside observers doubt whether the ship's engine, weapons systems and other electronic equipment can function normally, as parts of the warship were submerged for about two weeks. North Korea's failed launch on May 21 sparked fury from Kim, who has vowed to build a stronger navy to cope with what he calls escalating US-led threats against his country. 

Kim said the incident was caused by criminal negligence and ordered officials to repair the warship before a ruling Workers' Party meeting in late June. North Korean authorities later detained four officials including the vice director of the Workers' Party's munitions industry department over the botched launch. In his Thursday speech, Kim said the country's two destroyers will play a big role in improving the navy's operational capabilities, according to KCNA.

Kim reiterated previous claims that his naval buildup is a justified response to perceived threats posed by the US and South Korea, which in recent years have expanded their combined military exercises and updated their deterrence strategies to counter Kim's advancing nuclear programme.