Sudan and rebels from South Kordofan are to meet Thursday for their first peace talks in almost a year, aiming to end a war that has affected more than one million people.
The Ethiopia negotiations come two weeks after Sudan's President Omar al-Bashir appealed for a political and economic "renaissance," with peace as the top priority, in his war-ravaged and poverty-stricken nation.
Diplomats say the Addis Ababa talks signal recognition within Bashir's 25-year-old regime that its current course is unsustainable.
The talks could be the start of a much broader national dialogue, drawing in opposition parties and other groups, to address discontent in outlying areas and ease pressure on a sanctions-hit, indebted economy starved of hard currency since South Sudan separated in 2011.
"I have a sense that we are on the verge of something," an African diplomat said.
"But how deep it will go and how serious it will be is another question."
The African Union said it invited the government and Sudan People's Liberation Movement-North (SPLM-N) for the negotiations.
"Both parties have received the invitation and have accepted to attend," an AU statement said, urging a speedy settlement of the conflicts in the Kordofan region and Blue Nile state, where ethnic SPLM-N rebels have been fighting since 2011.
Short-lived negotiations between the two sides last April collapsed.
Critics of the wars and other government policy became increasingly vocal after September demonstrations against fuel price rises.
More than 200 people were believed killed, according to Amnesty International, with analysts saying the protests pointed to an urgent need for government reform.
"There are definitely people within the regime who want reforms," a Western diplomat said.
"They're not doing it for altruistic motives but recognising they don't want to go the way of Syria or other regimes around that have had Arab Springs."
Jonah Leff, of the Small Arms Survey, an independent Swiss-based research project, said the Addis talks are "a significant development" that reflect a political shift by the ruling National Congress Party.
The fighting in Kordofan and Blue Nile "must be sucking a lot of resources" from an economy desperate for hard currency, the Western diplomat said.
"And it is also one of the political obstacles to them engaging more with the international community and in getting more progress on debt relief," he said, asking for anonymity.
Sudan has more than $40 billion in debt, and is under a US trade embargo.
A civil war that began in South Sudan two months ago has added to Khartoum's economic misery.
Revenue from trans-shipping southern oil through Sudanese export pipelines is down about 20 percent, the diplomat said, after some southern oil fields were temporarily shut because of the fighting.
Despite the money it has spent on the wars, and its vows to crush the rebels, the African diplomat said "it's the same stalemate" in Kordofan and Blue Nile.
The wars there, and an older insurgency in the Darfur region, are fuelled by complaints of economic and political neglect by the Arab-dominated regime.
Analysts say the conflicts need to be addressed in a comprehensive national framework, not as separate problems as has been the government's practice.
Thursday's negotiations "will be launched in a very different atmosphere," as the government now accepts the need for a comprehensive solution, veteran columnist Mahjoub Mohamed Salih wrote in The Citizen.
In his "renaissance" speech, Bashir repeated an invitation he made over the past year for a broad political dialogue, including with the rebels.
But diplomats say there was also something new: a recognition by Bashir of the country's ethnic diversity.
"I think what we're waiting for now is the roadmap, and how it's going to be implemented," the Western diplomat said. "But at the moment it's still just words."