SEOUL, South Korea — North Korea named former premier Pak Pong-ju, a key confidant of the leadership dynasty who was sacked in 2007 for failing to implement economic reforms, as its Cabinet chief on Monday in a move that would further cement the ruling family's grip on power.

Pak, believed to be in his 70s, is a key ally of Jang Song Thaek, the uncle of the isolated state's young ruler Kim Jong Un, and worked for Jang's wife, Kim's aunt Kyong Hui, the last remaining personal link to the state's revolutionary founder, Kim Il Sung, grandfather of the current leader.

"At the session, Deputy Choe Yong-rim was recalled from the post of premier of the DPRK Cabinet and Deputy Pak Pong-ju was elected premier of the DPRK Cabinet," state news agency KCNA said, referring to a meeting of the rubber-stamp parliament.

DPRK is short for the North's official name, the Democratic People's Republic of Korea and the move came as tensions ratcheted higher on the Korean peninsula as Pyongyang threatened war and the United States flew in Stealth bombers.

Pak was named to the powerful ruling Workers' Party of Korea Central Committee political bureau on Sunday and his re-emergence as premier marks a further move by North Korea's young leader Kim Jong Un to reaffirm his grip on power.

The move does however leave Kim, the third of his line to rule the impoverished, nuclear-armed state, dangerously dependent on his aunt and uncle, who have reasserted control over the military in a purge.

"Pak Pong-ju works under the orders of Jang Song-thaek," said Cho Bong-hyun, an expert on the North's economy at the IBK Economic Institute. "Is Pak a reformer? Well, Jang is an economy focused man, and Jang is the person who has tried to make the economy the centerpiece for the leadership."

FAILED REFORMS

Pak is a career technocrat who took the post of premier in 2003 to implement an ambitious economic reform policy that allowed autonomy in farm production and pricing liberalization, introduced in July 2002.

He was removed in 2007 when it became clear the steps aimed at boosting the impoverished state's economy, gripped by devastating famine in the 1990s, were not producing desired results and the North's military began protests at the cabinet, wielding greater power on state matters.

Jang, Kim's uncle, was also purged and has since been rehabilitated.

Jang is officially a deputy chairman of the North's powerful National Defense Commission, which Kim heads despite his lack of military experience. He is believed to be the real power behind the throne as it struggles to boost its economy.

Jang was on a high-profile tour of rival South Korea's industrial successes in 2002 and pointedly had the new premier Pak as a key member of the delegation just as they were mandated by former leader Kim Jong-il to rescue the ailing economy.

"Pak's appointment shows in no uncertain terms that the North wants to focus on the economy," said Yang Moo-jin of University of North Korean Studies in Seoul.

The appointment of Pak comes as North Korea is engaged in a war of words with the United States and South Korea, threatening to launch missile attacks on the United States and to invade the South.

The North's leader Kim said at the party meeting on Sunday that his country's focus will be to revive the economy and boost its nuclear arsenal.

The shrill rhetoric from Pyongyang is in response to a U.N. Security Council Resolution imposing sanctions for the country's February nuclear test and to a build-up of U.S. forces in South Korea as part of military drills.

The North says that Washington's moves are "hostile" and a prelude to an invasion.