N. Korea swears loyalty to young leader NORTH Korean leader Kim Jong-Un has presided over a mass gathering of military and party officials that was broadcast live on state television at a time of growing concern over the stability of his hardline regime. It followed the shock execution last week of Kim Jong-Un's uncle and one-time political mentor, Jang Song-thaek. The purge raised questions about factional infighting at the top of the North Korean hierarchy and prompted both Seoul and Washington to warn of possible provocative acts by the nuclear-armed regime. "We should be warriors to safeguard the party centre with our lives ... with the conviction that we know no one but the great comrade Kim Jong-Un," North Korea's ceremonial head of state, Kim Yong-nam, said in an opening address. "By holding the respected comrade Kim Jong-Un in high esteem ... our country will prosper as the country of eternal sun," Kim Yong-nam said. Tuesday's mass meeting also heard a keynote address by top military leader Choe Ryong-hae - who some analysts believe had a hand in the ouster and execution of Jang. "Our revolutionary forces know ... no one but comrade Kim Jong-Un," said Choe, a close Kim Jong-Un confidant who holds the military rank of vice marshal and is director of the Korean People's Army's General Political Department The military will support "our supreme commander, under any storms and hardships," said Choe, who also fired off a warning at rival South Korea. At a meeting of top defence and national security officials on Monday, South Korean President Park Geun-hye had warned that the recent leadership shake-up in the North could presage some aggressive behaviour from Pyongyang. "We can't rule out the possibility of contingencies such as reckless provocations," Park said, urging the military to step up vigilance along the heavily fortified border. Meanwhile in New York UN Secretary-General Ban Ki-moon called Jang's execution "very dramatic and surprising" and urged the country's neighbours not to take any "premature actions," the AP reported. Ban, a former South Korean foreign minister, expressed hope there will be no increase of tensions on the Korean peninsula. In his first public comments on the execution, Ban also urged North Korea's leaders to work to denuclearise the peninsula. He stressed that North Korea must focus on improving the living conditions of its people and comply with Security Council resolutions, which it has long ignored.