SEOUL (REUTERS) - In one of the biggest leadership shake-ups in years, North Korea named a new nominal head of state and a new premier, and gave leader Kim Jong Un a new title, state media reported on Friday (April 12), moves analysts said solidify Mr Kim's grip on power.

In an expected move, Mr Kim Jong Un was re-elected as chairman of the State Affairs Commission at a session of North Korea's rubber-stamp legislature that took place on Thursday, Korean Central News Agency (KCNA) said.

For the first time, however, state media referred to Mr Kim as"supreme representative of all the Korean people." That title was approved by special decree in February, according to the Associated Press, but has not been used publicly until Friday.

It's unclear whether the changes will be codified in the constitution, but analysts said the shake-up shows Mr Kim has fully come into his own, eight years after he inherited rule from his father, Kim Jong Il.

"The transition and power consolidation of the Kim Jong Un regime is complete," said Mr Michael Madden, a leadership researcher with 38 North, a website that monitors North Korea. "This is probably the largest party-government shake-up in many years," he said.

Since early 2018, Mr Kim has embarked on a push for economic development and international engagement, including historic summits with the leaders of the United States, China and South Korea.

Mr Choe Ryong Hae was named President of the Presidium of the Supreme People's Assembly of North Korea, replacing Mr Kim Yong Nam.

The person holding that position is constitutionally considered North Korea's head of state and usually represents the country at diplomatic events, though experts say real power remains concentrated in Mr Kim Jong Un's hands.

Mr Kim Yong Nam, who was born in 1928, has been one of the longest serving senior officials, having held the position since it was created for him in 1998, Mr Madden said.

His replacement, Mr Choe, was subjected to political"re-education" in the past, but in recent years appeared to be gaining more influence since he was promoted in October 2017 to the party's powerful Central Military Commission, South Korean intelligence officials previously said.

Mr Choe, born in 1950, was one of the most powerful officials in North Korea as head of the Workers' Party of Korea Organisation and Guidance Department, and had been director of cultural exchange programmes and vice-chairman at the Kim Il Sung Youth League in the 1980s, leading youth delegations on goodwill visits to China, Russia, Japan, Libya and Greece, according to database North Korea Leadership Watch.

He is a second-generation revolutionary and personally knew the late Kim Jong Il, Mr Kim Jong Un's father, for over 50 years, North Korea Leadership Watch said.

Mr Choe was one of the three officials sanctioned by the US in December over allegations of rights abuses.

On Thursday, US President Donald Trump, who has had two summits with Mr Kim to discuss North Korean denuclearisation and has expressed his willingness for a third, said Washington would leave sanctions in place.

Several officials who have played leading roles in negotiations with the United States, including Ms Choe Son Hui and Mr Kim Yong Chol, were also promoted.

ECONOMIC REFORMS

North Korea also replaced the premier of its Cabinet, Mr Pak Pong Ju, an official at the centre of efforts to jumpstart the economy. He had served in the post of premier since 2013.

Mr Kim has made economic development the centrepiece of his strategy and told officials this week that building a self-supporting economy would be a blow to the "hostile forces" that have imposed sanctions on the North Korea.

According to analysts at NK News, a website that monitors North Korea, Mr Pak helped oversee a process of "radical reform" in the economy that helped it survive sanctions.

Among those reforms were loosening control of state-run enterprises, allowing them to operate more freely in the market and to seek private investment, according to a 2017 profile of Mr Pak in NK News.

Some of those reforms earned the ire of Mr Kim Jong Il, who led North Korea at the time. But the younger Kim has more openly embraced many of those market changes, and North Korea has sought to ease sanctions and attract more private investment.

Mr Pak will now serve as a vice chairman of the ruling party, meaning that those economic reforms are still being embraced, said Mr Hong Min, senior researcher of Korea Institute for National Unification in Seoul.

"It means Pak Pong Ju-nomics, or Pak Pong Ju-style economic reform is continuing," he said.

There is little known about Mr Pak's replacement, Mr Kim Jae Ryong, who has been serving as a party leader in Jagang Province, a mountainous area home to some munitions factories.

The province is known within North Korea, however, for having a spirit of overcoming hardship, which may fit with Mr Kim Jong Un's message of persevering under sanctions, Mr Hong said.