The authorities of the Democratic People's Republic of Korea (DPRK) on Monday called on the nation to remain loyal to Kim Jong Un, son of late leader Kim Jong Il, and further cement the "single-minded unity of the party, the army and the people."

DPRK top leader Kim Jong-il [File photo]

The appeal came in a notice published by the DPRK's official KCNA news agency following the announcement of the death of Kim Jong Il, general secretary of the Workers' Party of Korea (WPK), by the DPRK's state TV.

Kim Jong Il, also chairman of the DPRK National Defense Commission and supreme commander of the Korean People's Army (KPA), died of "great mental and physical strain" at 8:30 a.m. Saturday (2330 GMT Friday) on a train during a field guidance tour, the KCNA reported.

"Kim Jong Il passed away to our regret before seeing the victory of the cause of building a thriving nation, the national reunification... but laid a strong political and military base for ensuring the steady advance of the Korean revolution through generations and provided a solid foundation for the eternal prosperity of the country and the nation," the notice said.

"All the party members, servicepersons and people should remain loyal to the guidance of respected Kim Jong Un and firmly protect and further cement the single-minded unity of the party, the army and the people," it said.

Kim Jong Un, son of Kim Jong Il [File photo]

It urged the nation to turn sorrow into strength and courage under the leadership of Kim Jong Un and overcome the present difficulties and work harder for a great victory.

"Our army and people will hold leader Kim Jong Il in high esteem forever with unshakable faith and a noble sense of moral obligation," the notice said.

"We should increase the country's military capability in every way to reliably safeguard the Korean socialist system and the gains of revolution... thus bringing about a decisive turn in building an economic power and improving the standard of people's living," it continued.

"We will surely achieve the independent reunification of the country by concerted efforts of all Koreans by thoroughly implementing the Three Charters for National Reunification and the North-South joint declarations," the notice said.

"Our party and people will strive hard to boost friendship and solidarity with the peoples of different countries, guided by the idea of independence, peace and friendship, and build an independent and peaceful new world free from domination, subjugation, aggression and war," it said.

"No force on Earth can check the revolutionary advance of our party, army and people," the notice added.