A foreign ministry statement said on the eve of the anniversary: "Sudan and its national government renews its steadfast determination to implement all the articles of the peace agreement."
On 9 January 2005, the Muslim government of Omar al-Bashir, Sudan's president, and the mainly Christian southern rebels signed the deal that put an end to a civil war that lasted 21 years, killed 1.5 million people and displaced four million.
Its main partners, al-Bashir's National Congress Party (NCP) and the southern Sudan People's Liberation Movement (SPLM) of Salva Kiir, are organising events to mark the anniversary.
Celebrations will culminate later on Monday in Juba, the capital of the south, with an event to be kicked off with a speech by southern leader Kiir, who is also Sudan's first vice-president.
Delegates from the Intergovernmental Agency on Development (IGAD), the east African group that sponsored the talks that led to the signing of the deal, were also expected to attend, along with other dignitaries.
Thousands of people began flocking to the event's venue, the Peace Square, early in the morning, with cultural shows and performances and other entertainment scheduled throughout the day.
When Garang died, Salva Kiir
became first vice-president
But aid agencies say there is little cause for celebration, as the people have yet to see dividends on the ground, and conflict continues in Darfur and in the east of the country.
Sorcha O'Callaghan, spokesperson for a coalition of six international aid agencies operating in Sudan, said: "The peace agreement signed a year ago was a momentous achievement.
"With conflict still raging in Darfur and insecurity in the south and east of the country, many Sudanese have little to celebrate."
The war between government forces and ethnic minority rebels in Darfur has left as many as 300,000 people dead and an estimated 2.5 million displaced, creating what the UN called the world's worst humanitarian crisis.
Many had hailed the north-south peace deal as an historic achievement and expressed optimism that it could be used as a model to resolve the country's other conflicts.
The UN described Darfur as the
world's worst humanitarian crisis
"Sudan hopes the peace will continue to strengthen and that the crisis in Darfur will be overcome in the same way peace was achieved in the south," according to the foreign ministry statement.
It also called on the international community to deliver on pledges it made at a donors' conference in Norway last April for $4.5 billion in development assistance for war-affected areas of Sudan.
The aid agencies said: "Delays have meant that little has reached the struggling communities who are trying to rebuild their lives."
Analysts said the agreement is still threatened on several fronts, including a reluctance by the north to loosen its grip on power and a south already leaning towards independence.
They also argue that the international community has fallen short of its pledge to prop up the north-south peace deal, offering massive humanitarian aid but failing to assist the political process.
Lam Akol, the foreign minister, urged Washington to support the peace and reiterated an appeal for financial pledges to be paid during a meeting with US congressman Jim Kolbe on Sunday.
"The challenge this year is to make sure that people of Sudan really feel the benefits of peace"
Aid agencies joint statement
The death of John Garang, the SPLM's leader, in a helicopter crash in July also dealt a serious blow to a peace process he had come to symbolise.
The aid agencies said: "The challenge this year is to make sure that people of Sudan really feel the benefits of peace."