North Korea has commemorated Kim Jong Il's 70th birthday with the flowers that bear his name, a military parade and pledges of loyalty to the son who has taken his place.

New leader Kim Jong Un, wearing a dark Mao-style suit and a solemn expression, bowed deeply before a large portrait of his smiling father in Kumsusan Memorial Palace in Pyongyang, the capital. Hundreds of senior officials, military leaders and citizens followed to pay their respects. Outside the palace, thousands of North Korean soldiers lined up in neat rows on a sunny but cold day, listening to speeches praising the Kim family.

Later, the new leader and other officials watched as a parade of soldiers marched by, followed by military vehicles and trucks carrying artillery guns and rocket launchers. Fireworks exploded, military music boomed and people waved artificial pink and red flowers.

Since Kim Jong Il's funeral nearly two months ago, North Korea's leadership and state media have cast him as a strong but benevolent leader, while praising Kim Jong Un as the unquestioned choice to succeed him in this socialist nation of 24 million.

Events included an international skating show and a synchronised swimming show. Both opened with mournful odes to Kim Jong Il and ended with a new song for his son: "We Will Defend General Kim Jong Un at the Risk of Our Lives."

Kim Jong Il ruled with an iron fist for 17 years, a period that included a famine in the 1990s that killed hundreds of thousands of people and protracted tensions over the nation's drive to build nuclear weapons.

Food shortages persist in North Korea and relations with South Korea are at their lowest point in years. However since Kim's death, expressions of mourning and adoration have been common in Pyongyang.

At Kim Il Sung Square, the main plaza in the capital, North Koreans bowed and laid flowers, including red "kimjongilia" begonias, at a portrait of Kim Jong Il hanging on the Grand People's Study House.

The memorial could serve as closure to North Korea's mourning ahead of important nuclear talks next week with the United States, said John Delury, an assistant professor at Yonsei University's Graduate School of International Studies in South Korea.

Kim Jong Il's death halted discussions between Pyongyang and Washington on much-needed food aid in exchange for nuclear disarmament. North Korea has tested two atomic devices since 2006.