North Korea has welcomed the New Year with a message saying the army, ruling party and people will become "human shields" to defend Kim Jong Il's son and successor "unto death".

The North also said in its annual message that the country must "launch an all-out drive" to achieve prosperity.

This year marks the centennial of the birth of new leader Kim Jong Un's grandfather, the revered national founder Kim Il Sung.

The New Year's message comes weeks after Kim Jong Il's December 17 death.

North Korea in recent days has cemented Kim Jong Un's position as leader of the country.

On Saturday, North Korea officially named him Supreme Commander over the 1.2 million-strong military.

The message said: "Glorify this year 2012 as a year of proud victory, a year when an era of prosperity is unfolding. The whole party, the entire army and all the people should possess a firm conviction that they will become human bulwarks and human shields in defending Kim Jong Un unto death."

North Korea's traditional New Year's Day message is always closely watched for clues to the government's plans. It takes on added significance this year coming just two weeks after the death of Kim Jong Il.