North Korean leader Kim Jong-un has led his nation in celebrating his recently deceased father's official 70th birthday, two months after assuming power.

Dressed in a black Mao-style suit, a smiling Kim resembled his grandfather Kim Il-sung as he presided over a lavish military parade in honor of Kim Jong-Il.

Thursday's public appearance by the new ruler comes just days after bizarre Twitter rumors announcing his assassination spread across the internet.

It is believed the rumors originated in China, after a man working near the North Korean embassy building noticed 30 or so cars parked outside and posted on Chinese micro blogging site Sina Weibo, 'Did something happen in Korea?'

Kim Jong-un, the third member of the family to lead the Hermit Kingdom, appeared in front of hundreds of senior officials, military leaders and citizens at Kumsusan Memorial Palace in the capital Pyongyang.

Thousands of soldiers, tanks, trucks and artillery guns paraded past Kim Jong-un's viewing platform as he stood beneath a giant portrait of Kim Jong Il.

According to the Associated Press, Ri Yong Ho, vice marshal of the Korean People's Army and the military's General Staff chief, said in a speech: Bearing guns, we will faithfully uphold the 'military-first' leadership of our respected supreme commander and comrade.

Let's dedicate our lives to protect Kim Jong-un! troops in the plaza roared in reply.

Since the death of his father, the young Kim Jong-un has conducted a dozen or so field inspections mostly to military units and has been pictured smiling with troops in sharp contrast to Kim Jong-il's austere rule.

He has been seen holding hands with top brass, linking arms with women cadres and chatting to ordinary soldiers.

He does seem to be genuinely enjoying the photo opportunities, even the physical contact with people, more than his two predecessors did, but that could just be because he's new to all this, says Brian Myers, an expert on North Korean propaganda at South Korea's Dongseo University.

According to North Korea watchers, Kim Jong-un's uncharacteristically jovial body language is considered so unusual that it could be seen as a sign of weakness.

Experts have speculated that Kim Jong-un's carefree outward appearance is a deliberate ploy to mask the fact he shares power with his influential uncle Jang Song-thaek, as well as the army head, Ri Yong-ho.