North Korea said Sunday in its annual New Year's message that it will stage an all-out drive toward prosperity, with its army, ruling party and people ready to defend Kim Jong Il's young son and successor "unto death."

The North's message, released by the official Korean Central News Agency, comes as the country enters a new era, with Kim Jong Un firmly installed as Supreme Commander of the military and ruling party leader following his father's Dec. 17 death.

This year also marks a crucial one in the North's history as it works on its goal to build a "great and prosperous nation" befitting the April 2012 centenary of the birth of national founder Kim Il Sung, the new leader's grandfather.

"Glorify this year 2012 as a year of proud victory, a year when an era of prosperity is unfolding," the North said. "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 longtime leader Kim Jong Il.

North Korea in recent days has cemented Kim Jong Un's position as leader, and on Saturday officially named him Supreme Commander over the 1.2 million-strong military.