North Korean youths have been urged to turn into "five million nuclear bombs" to protect the country's leader Kim Jong-un, during a recent gathering of the youth congress. Kim has also renamed the youth association, started by the North's late founder, reportedly to strengthen his grip on the country.

The Korean Children's Union (KCU), an organisation that is made up of all North Korean children aged between seven and 13, exhorted the country's younger generation to take up the mantle of guarding Kim in the coming years.

"Please be 'five million nuclear bombs' to protect our Dear Respected leader with your life as the men safeguarding the centre of the party, based on a strong belief and will," the KCU said in its statement, widely carried by state-run media outlets.

Kim had recently held the ninth congress of Kim Il Sung Socialist Youth League, which has about five million members in ages ranging from 14 to 30, in order to drum up support from younger North Koreans in cementing his power. This is the first such gathering of the association in 23 years after the previous one took place in February 1993. At the recent event, the organisation was also renamed the Kimilsungist-Kimjongilist Youth League.

"Youth league organisations and youth should become the vanguard and shock brigade in building a socialist power," Kim told the conference. "All the young Koreans in the north, the south and abroad should pool their will and intention and achieve solidarity and alliance in the patriotic struggle for reunification under the unfurled banner of national independence and great national unity and thus foil the obstructions of the US imperialists and anti-reunification forces and pave a wide avenue to national reunification."

The congress took place when Kim's regime is facing testing times over a series of high-profile defections from the country. South Korea has said the event largely symbolises Kim's intention to solicit support from young North Koreans so as to allow him to tighten his control on the isolated country.

"By eliminating the word socialist from the name of the youth league, North Korea made clear the characteristic of the group. The league has become a group of followers for the hereditary dynasty of Kim's family from that of a socialist association," Jeong Joon-hee, a spokesman with the South Korean unification ministry, told reporters.