"Hyon Yong-chol was awarded the title of vice marshal of the Korean People's Army," said the KCNA, the communist nation's state media Korean Central News Agency.
"A decision on awarding the title was made by the Central Military Commission of the Workers' Party of Korea and the National Defense Commission of the DPRK on Monday," it added in a brief dispatch, monitored in Seoul. DPRK is the acronym for the North's formal name, the Democratic People's Republic of Korea.
Little known to the outside world, Hyon is widely assumed to be in his early 60s and to have served in a field army in charge of border defense.
How exactly old Hyon is or where and what university he is from are barely known to the local press and even to government officials.
He is one of several figures who became emerging stars under the Kim Jong-un regime, among them is Choe Ryong-hae, the director of the General Political Bureau of the (North) Korean People's Army.
Hyon was promoted to a four-star general in September 2010 when Kim Jong-un was also awarded the same rank in the North's first clearest signal over the power transfer to Kim Jong-il's youngest son.
The follow-up personnel decision came one day after the North made a unexpected announcement over the dismissal of Vice Marshal Ri Yong-ho, well known for his key role in paving the way for the young leader to take over power after the death of his father Kim Jong-il in December last year.
Citing illness, the North relieved Ri of all his posts at the Workers' Party of (North) Korea, and the Presidium of the Political Bureau. Ri is also interpreted to have also lost his position as the army's chief of General Staff.
Hyon's surprise ascent to the core of the governing military class heralds a far-reaching reshuffle or a shift in generations within the military, experts well versed in North Korean issues said.
"Promoting a field-grade officer to a key military post signals that Kim Jong-un is attempting to reorganize the military structure with figures close to him," a senior official said, requesting anonymity due to the sensitivity of the issue.
Also fueling media speculation over the possibility of a power struggle as the reason for the unusually hasty personnel decision, another government official said the dismissal of Ri looks like a politically driven purging case aimed at solidifying Kim Jong-un's one-man dictatorship.
"There may have been conflicts between Kim Jong-un's relatives and the new military power group in the background (of the dismissal)," the official said on condition of anonymity.
The dismissal is "a powerful warning message to the new military power group, which could be a potential obstacle to the consolidation of the one-man dictatorship," the official also said.
The Kim Jong-un regime, believed to be closely shepherded by his uncle Jang Song-thaek, has taken several actions to deflate the military power group, the official said, referring to the quick rise of Choe Ryong-hae, a non-military official, as well as the removal of a foreign-currency income unit from the military.
As the military power group, which is generally opposed to changes, has been weakened by the new development, economic improvement measures that the North is reportedly reviewing could now get a boost, the official noted.
But the disgruntled military officials could also bring about serious political unrest should they try to speak out and launch a counterattack, he said.
Going forward, Kim, who is not yet 30, could give favors to military officers with a political background rather than to only those with military careers, Baek Seung-joo of the Korea Institute for Defense Analyses said. Baek added that the political department of the armed forces is expected to play a greater role in the communist state.