BEIJING - The Democratic People's Republic of Korea (DPRK) is calling Kim Jong-il's son a "great successor" to the country's guiding principle of self-reliance, as the country rallies around Kim Jong-un as its next leader.

As the people of the DPRK mourn the death of Kim Jong-il, the nation's official media called on them to rally around Kim Jong-un, who is in his late 20s and was last year made a four-star general and appointed to a top post in the Workers' Party of Korea (WPK).

The DPRK's official Korean Central News Agency (KCNA) said the country, people and military "should remain loyal to the guidance of respected Kim Jong-un".

"All party members, servicepersons and people should faithfully follow the leadership of comrade Kim Jong-un, and protect and further strengthen the unified front of the party, military and the public," said a female announcer on DPRK television, clad in a black Korean traditional dress and her voice choked with tears.

The statements from the DPRK clearly indicated that Kim Jong-un is already firmly in power, and senior officials had decided in the two days since Kim Jong-il's death to support Kim Jong-un as the new leader, said Lu Chao, a senior researcher at Liaoning Academy of Social Sciences.

Kim Jong-il, who suffered a stroke in August 2008 that left him with impaired movement in his left arm and leg, unveiled his third son Kim Jong-un as his successor a year ago, putting him in high-ranking political and military posts, and Kim Jong-un had regularly accompanied his father on trips around the country over the past year.

KCNA, quoting a statement from the national funeral committee of more than 200 people headed by Kim Jong-un, said Kim Jong-il's funeral will be held on Dec 28 in Pyongyang but no foreign delegations will be invited. A period of national mourning was declared from Dec 17 to 29.

Aside from Kim Jong-un, members of the DPRK's top governing body, the Presidium of the Political Bureau of the WPK Central Committee, are top legislator Kim Yong-nam, 83, Premier Choe Yong-rim, 81, and Vice-Marshal Ri Yong-ho, 69.

The first formal mention of Kim Jong-un's name in official state communications came just over a year ago, when he was promoted to the rank of four-star general in October 2010 just before a conference of the WPK.

He is believed to have studied in Switzerland and is thought to be capable of speaking some English and German, and possibly some French.

Analysts said whether he could quickly exercise control over the situation was worthy of attention.

"His approach would probably have no visible differences from his father, and the DPRK would continue its friendly relations with China," said Lu.

The DPRK's leadership style could be changed because Kim Jong-un is young and his experience of studying overseas could lead him to support economic reforms and opening to the outside world, he added.

AP, AFP and Liu Ce in Shenyang contributed to this story.