The referendum is over, southern independence is assured and Sudan has won rare praise and promises of improved US relations but Khartoum must now tackle Darfur.
Washington has initiated the process of removing Sudan from a terrorism blacklist as a reward to Khartoum for allowing last month's poll to go ahead peacefully and accepting the outcome.
The final results, confirmed on Monday, delivered a landslide for the south Sudan's secession from the north, showing nearly 99% of voters in favour of dividing Africa's biggest country.
US officials said on Tuesday it will take about six months to remove the state sponsor of terrorism designation, which carries sanctions and restrictions on loans and high-technology exports.
But aid agencies in Sudan are warning that Darfur has slipped down the international agenda just at a time of renewed fighting between rebels and the Sudanese army.
Clashes in Darfur have forced more than 43,000 people to flee their homes since December, according to UN estimates.
"There are huge challenges that need addressing in Darfur, where the conflict is no closer to being resolved," said Oxfam's regional spokesman Alun McDonald. "In just the past few weeks, there have been new bombings, new fighting and thousands of people fleeing their villages, particularly in North Darfur."
Northern opposition leaders have also warned that southern independence will stoke separatist movements in Darfur and other restive parts of the north.
Sudan's President Omar al-Bashir, meanwhile, is unable to meet Western leaders after being indicted by the International Criminal Court in 2009 on charges of war crimes and crimes against humanity over the conflict in Darfur.
US officials say they have not forgotten Sudan's troubled western region.
President Barack Obama called for a definitive end to the Darfur conflict after congratulating the people of south Sudan on their "successful and inspiring referendum."
At least 300,000 people have been killed in the Darfur conflict since non-Arab rebels first rose up against the Arab-dominated regime in Khartoum in 2003, according to the UN. Khartoum says 10,000 people have died.
US envoy Scott Gration, who wrapped up a trip to Darfur on Monday evening, acknowledged that the security situation there, while "a lot better" in some places, had deteriorated elsewhere.
"There are other areas where there is an increase in operations and people are being displaced and it is of course our desire to see that the fighting between the rebels and the government come to an end, to see a negotiated ceasefire," Gration told reporters in Khartoum.
But negotiations have been deadlocked since December when the government recalled its delegation to Darfur peace talks in Qatar, citing a lack of progress.
The Justice and Equality Movement, the most heavily armed rebel group, said in late January that it was ready for talks, but only if they addressed the root causes of the conflict, including political marginalisation and refugees.
Sudan's Foreign Minister Ali Karti suggested on Tuesday that Khartoum had struck a deal with the United States over Darfur, while expressing concern that US pressure groups would seek to exploit the latest violence.
"There is an agreement between Sudan and the United States that Darfur should not block relations between the two countries and should be an area of cooperation for achieving peace there," Karti said.
"We hope that the situation on the ground in Darfur doesn't give those groups who have an agenda the chance to benefit from that," he added.
After meeting Karti, Gration hailed the "great steps" the government had taken to facilitate the movement of international NGOs and the joint African Union-UN peacekeeping force (UNAMID) in Sudan.
But in recent weeks aid workers and UNAMID itself have strongly complained about restrictions on movement in Darfur, whether because of security concerns or obstruction by government troops.
In one incident, the Sudanese army threatened to "burn to the ground" makeshift camps in North Darfur, for people left homeless by the conflict, if the peacekeepers failed to stop "interfering in the government's internal affairs," a UNAMID source told AFP.
An aid worker based in Khartoum said some of the attacks around the South Darfur town of Khor Abeche in December, which displaced around 33,000 people, were particularly bad.
"It's been a very long time since we last saw villages being burnt. The information that we have from Darfur is that SAF (the Sudanese army) are using proxy militias," he said.