Kim Jong Un, who is in his late 20s and was revealed last year as his father's choice among three sons for successor, is the third generation Kim to rule the nation of 24 million. He was named a vice chairman of the Central Military Commission of the Workers' Party, but was expected to ascend to new military and political posts while being groomed to become the next leader.
Monday's reference to his new title was in commentary in the Rodong Sinmun newspaper, the mouthpiece of the Workers' Party. It came as two private South Korean delegations arrived in Pyongyang to pay their respects to Kim Jong Il.
The slogan, which state media had frequently used when rallying support for Kim Jong Il, made clear the son is quickly moving toward leadership of the Workers' Party, one of the country's highest positions, in addition to the military.
Rodong Sinmun on Sunday urged the people to become "eternal revolutionary comrades" with Kim Jong Un, "the sun of the 21st century."
North Korea refers to Kim Il Sung as the "sun" of the nation and his birthday is celebrated as the "Day of the Sun," and state media has sought to emphasize Kim Jong Un's role in carrying out the Kim family legacy throughout his succession movement.
State television showed footage Sunday of Kim Jong Un's uncle and key patron, Jang Song Thaek, in a military uniform with a general's insignia. It was the first time that Jang, who was promoted last year to vice chairman of the Central Military Commission of the Workers' Party along with Kim Jong Un, was shown on state TV in military garb.
Mourning continued, meanwhile, despite frigid winter weather. Kim Jong Il's funeral is set to take place Wednesday and a memorial Thursday.
People continued lining up Monday in central Kim Il Sung Square, where a massive portrait that usually features Kim Il Sung has been replaced by one of Kim Jong Il, to bow before his smiling image and to lay funereal flowers. Heated buses stood by to give mourners a respite from the cold, and hot tea and water were distributed from beverage kiosks.
Two groups of South Koreans were among the mourners in Pyongyang. They crossed the heavily fortified border for a two-day trip that includes a visit to Kumsusan Memorial Palace where Kim's body is lying in state, according to Seoul's Unification Ministry.
The two groups are led by the widow of former President Kim Dae-jung, the creator of the engagement ``sunshine'' policy with the North who held a landmark summit with Kim in 2000, and Hyundai Group Chairwoman Hyun Jeong-eun, whose late husband had ties to the North. The North sent delegations to South Korea when the women's husbands died.