Armed with paint brushes and pruning shears, tens of thousands of people have been working night and day to spruce up Pyongyang for the centenary of North Korea's founding president and the coming to power of his grandson.

For nearly two months, foreign residents of Pyongyang say, workers have been busy cleaning, repairing, painting and planting to give the isolated communist state's capital a facelift for this weekend's celebrations.

The city's three million strictly regimented inhabitants were last out in force in late December for the funeral of longtime leader Kim Jong-Il, a carefully choreographed event that saw grief-ridden scenes of mass hysteria.

Similar scenes at the opposite end of the emotional spectrum are likely on Sunday, the 100th anniversary of the birth of Kim Il-Sung, Jong-Il's father who led the fight against occupying Japanese forces and ruled North Korea from 1948 until his death in 1994.

Now, after another dynastic succession, Kim Jong-Un is expected to take pride of place on Sunday in the stands overlooking Pyongyang's vast Kim Il-Sung Square, which can accommodate 100,000 people.

Kim Jong-Un, who is in his late 20s, is expected to be appointed secretary general of the Workers' Party of Korea and chairman of the National Defence Commission, the two highest posts held by his father Kim Jong-Il.

Foreign journalists have been granted entry to North Korea in rare numbers for the centenary commemorations but are dogged as ever by official minders, watching closely to see they do not go astray.

Rehearsals seen by the journalists indicate that Sunday will feature songs and dances, punctuated by living tableaux and processions of floral floats.

Every day until evening, thousands of young boys and girls, some in traditional dress, have gathered on Kim Il-Sung Square to rehearse the movements and dances they will perform.

The celebrations look set to climax with a parade to show off the regime's military might, in a country where the armed forces enjoy the lion's share of state resources while millions, according to UN agencies, go malnourished.

And sometime between Thursday and Monday, depending on the weather, North Korea will launch a rocket from a new space centre in the northwest, ostensibly to place a satellite in orbit.

In Pyongyang, with the coming of spring, authorities have mobilised the citizenry to make the city look its best.

Women armed with long-handled rollers lean out of the windows of buildings along Pyongyang's main streets to add a lick of paint to the crumbling facades.

Down below, workers wearing caps and armed with tins of tar mend holes in the road. There is barely any traffic to disturb them.

In the parks and flowerbeds along the avenues, women gather up litter and dead branches while gardeners prune the trees and replant.

On Sunday thousands of wreaths of "Kimilsungia" and "Kimjongilia" flowers, named after the two late leaders, will be offered as the armed forces, party officials and ministries pay their respects.

Bundles of red flags have been unfurled at crossroads. At night, when most of the streets are plunged into darkness in the electricity-starved city, the outlines of public buildings are illuminated with hundreds of bulbs.

On Kim Il-Sung Square, portraits of Marx and Lenin that normally adorn the west side -- the facade of the commerce ministry -- have been taken down to make way for two red banners glorifying North Korea's young new leader.

On the eastern side of the square, a giant portrait of Kim Il-Sung covers the facade of the agriculture ministry.

Behind the building, several 50-storey residential tower blocks have been erected in just a few months, which North Korea boasts are proof that it can defy Western sanctions and this year become a "powerful and prosperous state".

A hundred metres (yards) away, on the Jang Dae-Jae hill, two huge portraits of Kim Il-Sung and Kim Jong-Il beaming down on the city were unveiled Monday in front of several thousand guests.

As night fell, groups of students continued to file past to leave artificial flowers at the foot of the portraits. But down the small hill, few passersby cast a glance at the two former leaders.