PYONGYANG, North Korea (AP) ― Pumping their fists and chanting, tens of thousands of North Koreans packed the snowy main square of the capital Tuesday to pledge their loyalty to new leader Kim Jong-un as the campaign to consolidate his power deepened.

State television also aired footage of Kim’s recent visit to an elite tank unit with family and historical ties that showed him interacting with soldiers with ease and carrying out inspections much like father Kim Jong-il and grandfather Kim Il-sung did before him ― footage that aimed to show off his youth and health and put his confidence and authority on display.

The rally and the footage were the latest steps in a carefully choreographed campaign to build support for North Korea’s new leader that began the day news broke of Kim Jong-il’s death last month. In swift succession, top officials from the powerful military and ruling Workers’ Party have pledged their loyalty to the son, leaving no room for doubt about whether the young man would take power.

In the documentary of his military visit Sunday, he was dressed in a long, dark overcoat similar to the coat his grandfather used to wear. He is shown in an exhibition room lined with black-and-white photos, including an image portraying a young Kim Il-sung.

The footage also served to show the confidence of Kim, who mingled easily with soldiers and appeared to be giving them pointers in the documentary shown just days after the ruling party officially proclaimed him supreme commander of the 1.2-million-strong Korean People’s Army.

Soldiers cheered and chanted his name as Kim made an inaugural solo trip to provide ``on-the-spot guidance’’ in the first official documentary of the new leader shown on North Korean TV. At one point, Kim leaned in to pull one man close to him to share a few words, leaving the officer in tears.

``Kim Jong-un’s telling the world that even though he’s young, he’s in charge and capable of wielding a saber like this father did,” said Kim Jin-moo, a North Korea expert at the Korea Institute for Defense Analyses in South Korea.

Unlike his father, Kim Jong-un is not observing a three-year mourning period after his father’s death. He has been active, using his youth as an advantage, and distinctly public in stark contrast to his father, whose appearances were carefully calculated in the final years of his life.

Even the choice of the tank unit was a nod to history: The Seoul Ryu Kyong Su 105 Guards Tank Division was one of the first North Korean units to enter Seoul in the early days of the 1950-53 Korean War, according to military experts. It was one of Kim Jong-il’s favorite bases to visit.

In Pyongyang, meanwhile, Premier Choe Yong-rim and other old guard figures who are Kim’s inner circle led a rally in support of the leader and the country’s goals for the new year.

``We once again keep deep in our minds that the victory of building a powerful and prosperous nation is certain, as long as there is the ... wise leadership of respected Comrade Kim Jong-un,” senior Workers’ Party official Mun Gyong Dok told the crowd at Kim Il Sung Square, according to Associated Press Television News.

Beating drums and carrying huge North Korean flags, they paraded across the square in central Pyongyang as snow fell, pumping their right fists as they chanted. Some held huge placards calling for loyalty to Kim and supporting efforts to improve the economy.

About 100,000 North Koreans attended the rally, officials said.