The funeral of former North Korean leader Kim Jong Il has begun in Pyongyang, where tens of thousands gathered for an extravagant two-day ceremony to cement his legacy and transfer power to his youngest son, Kim Jong Un.

Snow filled the gray skies as the funeral procession began early Wednesday. A black limousine with a huge portrait of the late leader led the procession through Pyongyang's snow-covered streets, followed by another limousine with Mr. Kim's flag-draped coffin resting atop on a bed of white flowers. Weeping mourners lined the streets, some pressing toward the procession as it passed, but held back by security guards.

Images broadcast on North Korea's state television showed Kim Jong Un walking alongside his father's hearse as it left the huge square of the Kumsusan Memorial Palace. Dressed in a dark overcoat, he bowed his head slightly against the snow and raised his right arm in salute. Soldiers filled the square as a color guard marched and a military band played solemn music.

Analysts expected the ceremony to be similar to that of Mr. Kim's father and founding president Kim Il Sung in 1994, which highlighted the hallmarks of his rule and strengthened loyalty to his dynastic successor.

Since Kim Jong Il died of a heart attack on December 17, state television has shown repeated scenes of extraordinary public grief throughout North Korea.

Foreign governments are watching events in Pyongyang closely because of concerns about the young Mr. Kim's rise in a country with a nuclear program, a large army and a history of deep animosity toward its neighbors.

Official media have been quick to declare Kim Jong Un as the “great successor,” supreme military commander and chief of the ruling Worker's Party.