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North Korea video marks leader Kim Jong-un's 'birthday'

8 January 2012 Last updated at 15:06 GMT

A documentary praising the military expertise of North Korea's new leader's Kim Jong-un has aired on what is believed to be his birthday.

The film shows Kim Jong-un in his new role as supreme military commander, inspecting troops, saluting and sitting in a tank.

It also confirms that he was being groomed for the role from 2009, showing footage of him from that time watching a rocket launch with his father.

Lucy Williamson reports from Seoul.