North Korean officials have pledged in their annual New Year's message to make every effort to bring the country to prosperity and to defend its new leader Kim Jong Un.

The message published Sunday by the state-run new agency KCNA comes a day after Mr. Kim was named the supreme commander of North Korea's military following his father Kim Jong Il's death.

In April, North Korea will mark a crucial landmark in its history: the centenary of the birth of its founder Kim Il Sung, the new leader's grandfather.

The New Year's message urges North Koreans to glorify 2012 as a year of victory and prosperity. It also calls on the army and people to defend Kim Jong Un unto death.

After the death of Kim Jong Il, December 17, North Korean official media referred to his youngest son as the great successor.

Kim Jong Un, who is in his 20s, was given a prominent position during his father's funeral. Leaders of the ruling Workers' Party officially named him supreme commander over the 1.2 million-strong military at a meeting Friday.

Officials also have sent a message to the world not to expect any changes in the communist country's policies.