SEOUL -- North Korea announced Friday that there would be no change in its policy under its new leader, Kim Jong Un, striking a characteristically hostile posture with a threat to punish South Korean President Lee Myung-bak for "unforgivable sins."
The statement from the National Defense Commission, North Korea's highest decision-making body, was the country's first official pronouncement to the outside world since the regime upheld Kim as its supreme leader Thursday.
He was elevated a day after the state funeral of his father, longtime dictator Kim Jong Il.
"We declare solemnly and confidently that the foolish politicians around the world, including the puppet group in South Korea, should not expect any change from us," the statement said.
"We will never deal with the traitor group of Lee Myung-bak."
The statement was carried by the Korean Central News Agency, the regime's official mouthpiece to the outside world.
On Saturday, North Korea officially named Kim Jong Un as supreme commander, putting him formally at the head of the 1.2 million-strong military and further strengthening his authority.
An unannounced Workers' Party meeting Friday proclaimed that Kim Jong Il's son and successor, who is in his late 20s, "assumed supreme commandership of the Korean People's Army" according to a will made by Kim Jong Il on Oct. 8, the nation's official news agency said Saturday.
The meeting of the North's ruling party was held one day after the official mourning period for Kim Jong Il ended and senior military and political officials publicly declared Kim Jong Un leader of the party, military, and people at a memorial for his father attended by hundreds of thousands.
Officials and state media have bestowed on Kim Jong Un a string of titles as North Korea's elite rally around him in the aftermath of his father's death Dec. 17.
But the title supreme commander -- and its formal approval by the powerful Political Bureau of the Central Committee of the Workers' Party -- is a clear sign that Kim Jong Un is fast consolidating power over North Korea.