People in the Democratic People's Republic of Korea bow before the statues of late leaders, Kim Il-sung, left, and Kim Jong-il, at Mansu Hill in Pyongyang on Monday. Sirens wailed for three minutes at noon in honor of the first anniversary of the death of Kim Jong-il. Ng Han-guan / Associated Press

The Democratic People's Republic of Korea held a national ceremony on Sunday to mark the first anniversary of the death of former leader Kim Jong-il.

Kim's successor, his youngest son, Kim Jong-un, attended the meeting along with other top officials of the ruling Workers' Party of Korea, government and army.

All the participants observed a moment of silence in memory of the senior Kim, who died of a heart attack on Dec 17, 2011. He had ruled the country for 17 years.

Kim Yong-nam, chairman of the Presidium of the Supreme People's Assembly, lauded the accomplishments of the late leader in his memorial address.

He said the senior Kim, who developed the Songun (military first) political theory and put forward the theory of building a thriving socialist nation, made the DPRK a world-level military power and legitimate nuclear weapon state.

Choe Ryong-hae, director of the Korean People's Army General Political Bureau, said in his speech that the armed forces of the DPRK will fully discharge their mission and role as the army of the leader, and the army of the party.

Jon Yong-nam, chairman of the Kim Il-sung Socialist Youth League Central Committee, pledged to follow the younger Kim.

The ceremony was held after the country celebrated its successful satellite launch on Wednesday.

The launch was condemned by the UN Security Council and seen by some countries as a disguised ballistic missile test.

Officials in black suits and uniformed military leaders convened in an indoor stadium in Pyongyang on Sunday morning for the hourlong memorial event, which was televised live on DPRK TV.

Kim Jong-un sat on stage with dozens of other top officials against the backdrop of a giant red flag featuring a large portrait of a smiling Kim Jong-il.

"The heart of the great leader stopped beating but Comrade Kim Jong-il lives with us forever ... to give blessings for the bright future of our people," Kim Yong-nam said in a speech.

"The successful launch of our Kwangmyongsong-2 satellite is also another victory achieved by our military and people, by faithfully following the teachings of the great leader," he said.

The DPRK said the apparently successful launch - its second after a botched mission in April - was a scientific project to put a weather satellite into orbit.

But the United States and other nations viewed it as a disguised ballistic missile test banned under UN resolutions triggered by its past nuclear tests in 2006 and 2009.

On Wednesday, the Security Council condemned the launch and said members "will continue consultations on an appropriate response".

Choe vowed to "hit back immediately" if the Republic of Korea or the United States provokes the nation, and he reaffirmed loyalty to the young leader.