When US state department officials realised that Colin Powell had a spare day-and-a-half between the end of the Nato summit in Istanbul and arriving in Jakarta for Asean-related meetings, there was no shortage of suggestions for where he might travel.
By Jill McGivering
BBC state department correspondent
The ultimate choice - Sudan - caused some surprise. Sudan is far from a normal destination for high-ranking US officials.
Food and water are running short for Darfur's refugees
But the decision was also a measure of the seriousness with which Washington views the current crisis in Darfur - and Mr Powell's determination to push it higher up the international agenda.
He arrived with a tough message - a demand for urgent action from the government in curbing the militias still dominating the region and allowing aid workers better access to the estimated 1.2 million villagers now taking refuge in makeshift camps because they have fled their homes and are still too terrified to go home.
Action, not words
His words were stark. "We're running out of time", he said, shortly before his meetings with Sudan's president and foreign minister.
"We need to see action promptly because people are dying and the death rates are going to go up significantly in the next several months. We've got to act now, not later. We can't talk. We have to see action."
He also contradicted the Sudanese officials' line that they are already doing what they can to stop the violence.
Powell came with a stern warning for Sudan
They deny directly supporting the Arab militia groups in the region, despite widespread allegations.
On the need to take control of the Arab militia, Mr Powell said clearly: "I believe they have the capacity to do that. We want to encourage them to have the will to do that and to do that right away."
Mr Powell also repeatedly described the humanitarian situation as a catastrophe, although he has tried to deflect attention away from the debate on whether the legal definition of genocide can and should be applied.
US figures suggest between 80,000 and 130,000 people in the camps could die before the end of this year if there is not dramatic intervention.
The rainy season is now starting - increasing the risk of water-borne diseases.
Aid agencies working in the camps estimate about 1 in 5 children are malnourished.
With only makeshift shelters, poor sanitation and cramped living conditions, disease can spread quickly and mean high death tolls amongst communities of children already weakened by lack of nourishment.
One aid worker described the situation as like being "on the edge of a precipice".
The initial response from Sudanese officials made some people wonder if Mr Powell's promised tough talking was really getting through at all.
Sudanese Foreign Minister Mustafa Osman Ismail in a joint press conference with Mr Powell after the initial top-level meetings, said there was no famine, no disease epidemic.
There was a humanitarian problem in Darfur, he said, but his tone suggested the sense of international alarm was exaggerated.
As Mr Powell flew out to Darfur to visit one camp for himself, a senior US state department official described Sudanese officials as being in "a state of denial, a state of avoidance" on Darfur.
The perception gap was clearly large - and frustrating.
Mr Powell's brief visit to Abu Shouk camp, close to El Fasher, gave him a dramatically first person taste of the plight of those most affected.
As the official convoy of jeeps drove through the dust and sand, in temperatures of about 37C, thousands of men, women and children, in brightly coloured traditional clothes, were already lining the entrance to the camp.
They ran, ululating, clapping and cheering, battling to keep up with the convoy as it circled the vast open expanse of desert, past neat rows and well-ordered blocks of plastic sheeting shelters.
The refugees hope Powell's visit will help them
Young boys scrambled onto the backs of aid trucks for a better view as the jeeps circled, heavily guarded by pick-up trucks filled with armed uniformed men.
When Mr Powell finally emerged and was guided through the sand by aid workers, he joined in the general applause.
The crowd, many of the 40,000 people sheltering here, were kept back by lines of security - but it was hard to suppress the sense of festival.
Mr Powell described the visit as "a very moving experience".
He said too that he knew this was one of the better camps. Aid workers told us it was often chosen to show to visitors.
But even well-run camps were no solution, he said. Accompanied by Sudan's foreign minister, he repeated the message that became a mantra here:
"We are anxious to see the Janjaweed [Arab militias] brought under control and disarmed so people can leave camps in safety and go back to their villages."
Security, he said, was the number one priority.
By the time Mr Powell was back in Khartoum and ready to leave, his constant reiteration of the same warning message, backed by the threat of a tougher UN Security Council resolution on Sudan and of potential damage to the fledgling North-South peace process currently being nurtured by Washington, seemed, at last, to be having an impact.
In a final press conference at the airport, Sudan's foreign minister made fresh pledges.
His government now intended to concentrate on three things, Mr Ismail said:
More police and security forces in Darfur to protect civilians and combat militias
The lifting of restrictions on humanitarian items to speed up the process of delivering supplies before the rainy season makes routes even more hazardous
Speeding up political negotiations, in co-operation with the African Union, to work out a solution to the crisis.
Mr Powell said the timetable agreed for action is immediate: "We're talking about days and weeks."
The question now will be whether those promises really are implemented actively and sincerely enough to help the hundreds and thousands of people still too scared to go home to their villages.
That will be the real test of Mr Powell's flying and outspoken visit.