PYONGYANG, North Korea - Kim Jong Il's son and successor was declared "supreme leader" of North Korea's ruling party, military, and the people during a memorial Thursday for his father in the first public endorsement of his leadership by the government.

Kim Jong Un, head bowed and somber in a dark overcoat, stood watching from a balcony at the Grand People's Study House overlooking Kim Il Sung Square, flanked by the top party and military officials and Kim Jong Il's younger sister.

Hundreds of thousands packed the square in central Pyongyang, filling the plaza from the Grand People's Study to the Taedong River for the second day of funeral ceremonies for the late leader.

Kim Jong Il, who led his 24 million people with absolute rule for 17 years, died of a heart attack Dec. 17 at age 69, according to state media. He had taken power after the 1994 death of his father, North Korea founder Kim Il Sung.

Soon after Kim Jong Il's death, attention turned to his son, who was revealed last year as his father's choice as successor.

Kim Jong Un, who is in his late 20s, serves as a vice chairman of the Central Military Commission of the ruling Workers' Party, but has been bestowed with a series of new titles in state media since his father's death: Great Successor, Supreme Leader, and Sagacious Leader.

"Respected Comrade Kim Jong Un is our party and military's supreme leader, who inherits great comrade Kim Jong Il's ideology, character, and revolutionary" cause, Kim Yong Nam, president of the Presidium of the Supreme People's Assembly and the ceremonial head of state, told the crowd Thursday. "The fact that he completely resolved the succession matter is great comrade Kim Jong Il's most noble achievement."

Kim Jong Un's leadership is not expected to become formal until top party, parliamentary, and government representatives convene to confirm his ascension.

The events have been watched closely for signs to who will take power in the next era of leadership in the country founded by Kim Il Sung in 1948 and led since then by the Kim family.

On Wednesday, hundreds of thousands of mourners had lined the streets as Kim Jong Il's hearse made its way through the snowy streets in a 21/2-hour funeral procession.

Kim Jong Un was head mourner, walking with one hand on the black hearse that carried his father's coffin on its roof, his other hand raised in salute, his head bowed against the wind.

At the end of the procession, rifles fired 21 times as Kim Jong Un stood flanked by the top party and military officials who are expected to be his inner circle of advisers. Kim then saluted again as goose-stepping soldiers carrying flags and rifles marched by.

Wednesday's procession had a stronger military presence than in 1994.

Mourners in parkas lined the streets of Pyongyang, waving, stamping, and crying as the convoy bearing the coffin passed. Some struggled to get past security personnel holding back the crowd.

"How can the sky not cry?" a weeping soldier standing in the snow said to state TV. "The people . . . are all crying tears of blood."

The dramatic scenes of grief showed how effectively North Korea built a personality cult around Kim Jong Il despite food shortages and decades of economic hardship.

A large challenge for North Korea's propaganda apparatus will be "to counter the public's perception that the new leader is a spoiled child of privilege," said Brian Myers, an expert on North Korean propaganda at Dongseo University in Busan, South Korea.

"Having Kim Jong Un trudge mournfully next to the hearse in terrible weather was a very clever move," Myers said.