MOUNT PAEKTU, North Korea (CBS) -- North Koreans on Tuesday (February 12) celebrated its successful nuclear test and pledged their loyalty to Kim Jong-un's regime.

The celebrations shown in video provided to Reuters by North Korea's official news agency KCNA, came ahead of late leader Kim Jong-il's birthday on February 16 which is known as the "Day of the Shining Star".

The footage showed government officials and military at a rally near the Jong-il Peak at Mount Paektu at the border area with China.

Soldiers said they felt proud of their country.

"Ahead of the meaningful "Day of Shining Star", I feel very proud to be a soldier after hearing the news of the successful nuclear test. The test sends a shock wave to the United States and its followers, who have called for sanctions over our satellite launch," said Kim Song-il, an officer of Korean People's Army.

"The news about the third nuclear test has greatly encouraged us soldiers. We're in high spirits which will enable us to crush any sanctions by the U.S. imperialists and their followers in one blow. I will fully prepare myself to be ready for any fight under our respected Supreme Commander Kim Jong-un's order. We're firmly pledging to support our country with our guns," said a North Korean soldier Ri Kum-song.

Kim Ki-nam, a secretary of the Central Committee of the Workers' Party of North Korea, hailed the late leader's military-first agenda.

"The great feats of leader Kim Jong-il who put the national defense capabilities to the highest level will remain long with the victorious development of Songun (military-first) Korea led by the respected comrade Kim Jong-un," he said.

The late Kim, who died of an apparent heart attack in December 2011, ruled the secretive and impoverished country for 17 years.

Kim Jong-un was named North Korea's "Great Successor" after his father's death in December 2011.

Pyongyang said on Tuesday that the test was an act of self-defense against "U.S. hostility" and threatened stronger steps if necessary.

North Korea's third nuclear test in defiance of a U.N. resolution drew condemnation from around the world, including China, its only major ally.

The United Nations Security Council also condemned the underground test, saying the latest move by Pyongyang was "a grave violation" of relevant resolutions.