The first observers are preparing to monitor a demilitarised buffer zone between Sudan and South Sudan, Khartoum's defence minister has said.
Analysts said both countries will face a major challenge to effectively implement the zone along their undemarcated and disputed frontier.
"The mechanism we agreed on has begun working," Defence Minister Abdelrahim Mohammed Hussein told reporters on Wednesday after returning from Addis Ababa.
For the first time, he also said his country was ready to engage in talks with the rebels who have been fighting for almost two years in South Kordofan and Blue Nile states.
Hussein said Sudanese monitors have since Tuesday been in the South Kordofan state capital, Kadugli, which will serve as temporary headquarters for the joint border monitoring teams.
"South Sudanese observers arrived today in Kadugli," he said.
The monitors, who will include United Nations peacekeepers, are to verify the withdrawal of Sudanese and South Sudanese forces from the buffer zone, 10 kilometres on each side of the 1956 border.
At talks in the Ethiopian capital this month, Sudan and South Sudan – which have engaged in months of intermittent clashes – finally settled on detailed timetables to ease tensions by implementing the buffer zone and key economic pacts.
The deals had remained dormant after their signing in September as Khartoum pushed for guarantees that South Sudan would no longer back rebels of the Sudan People's Liberation Movement-North (SPLM-N).
At the African Union-led talks in Addis Ababa, Sudan softened its stance on the security guarantees, helping the buffer zone and eight other agreements to go ahead, observers said.
The two countries have a history of signing pacts with each other but not following through.
South Sudan armed and trained SPLM-N when it was part of the South's rebel force but says it cut military ties before the South's independence in July 2011, following a Comprehensive Peace Agreement.
Analysts and diplomats say there is no doubt that South Sudan continued to back the rebels.
South Sudan says the north has supported insurgents on its territory, too.
The United Nations and the African Union have for months called on the SPLM-N and Khartoum to reach a negotiated settlement.
"We are ready to meet them," Hussein said in the first such statement by a government official.
But he said talks must occur "under the umbrella" of the agreement which, among other measures, called for a popular consultation in South Kordofan and Blue Nile.
SPLM-N has reiterated its readiness for direct negotiations with the government.
In a statement last Sunday, the US embassy in Khartoum said it welcomed a reported decision by the Sudanese government "to engage in AU-brokered talks with the Sudan People's Liberation Movement North".
It urged both parties to meet for those talks as soon as possible.
The war in South Kordofan and Blue Nile has forced more than 200 000 people to become refugees in South Sudan and Ethiopia.
An estimated one-million more have been affected inside the two states. – AFP.