North Korea unveiled a huge rock carving on Thursday in memory of founding leader Kim Il-Sung, as the impoverished country prepared a lavish celebration of this month's 100th anniversary of his birth.

The inscription covering a length of 37 meters (122 feet) was hewn into a natural rockface near Pakyon Falls in Kaesong city, near the border with South Korea, the official news agency said.

The message -- "Our eternal leader Comrade Kim Il-Sung: Dedicated to the centenary of the birth of the leader, April 15, Juche 101 (2012)" -- is "an immortal monument which will always shine along with the Songun era," the news agency said.

Songun is North Korea's military-first policy.

Kim Il-Sung died in 1994 and handed power to his son Kim Jong-Il, who died last December after bequeathing the leadership to his own son Kim Jong-Un.

The North, which fosters a massive personality cult surrounding the Kims, has inscribed messages praising the dynasty on hundreds of rocks and cliffsides.

A carving 120 meters wide was unveiled in February to mark the birthday of the late Kim Jong-Il.

Kim Il-Sung, whose body is preserved in a glass-enclosed bier, remains the country's "eternal president."

The poor but nuclear-armed nation is planning a massive celebration for the centenary, including a satellite launch widely condemned overseas as a covert missile test in defiance of UN resolutions.

Analysts say the regime is trying to build loyalty to the Kim dynasty and in particular to the young and untested new leader.

Work is continuing round the clock on apartment blocks and other construction projects timed to mark the anniversary, according to a foreign resident in the showpiece capital Pyongyang. (AFP)