The new United Nations Secretary-General Ban Ki-moon has finished his visit to Africa, his first and most extensive since taking office one month ago.
By Laura Trevelyan
UN correspondent, BBC News
The most significant encounter of Mr Ban's five-day visit to Africa took place in Addis Ababa on the fringes of the African Union summit.
Mr Ban (r) said he has trust in Sudan's President Bashir
For an hour the new secretary general and his top officials - including the head of UN peacekeeping Jean-Marie Guehenno - met President Omar al-Bashir of Sudan.
Then, for half an hour, Mr Ban and the Sudanese leader had what the secretary general called a tete-a-tete.
At issue is the four-year-old conflict in Darfur, where the Sudanese government and the Janjaweed militia it backs stand accused of mass killings as they attempt to defeat rebel groups in the west of the country.
Mr Ban has made resolving the crisis one of his priorities.
Some 200,000 people are estimated to have died, more than two million are homeless and the fighting has spilled over into the neighbouring countries of Chad and the Central African Republic.
Aid agencies say there is a humanitarian crisis not only in Darfur but also in the refugee camps across the borders.
The Darfur peace agreement, supposed to stop the fighting, has not been signed by all the rebel groups.
The African Union peacekeeping force in Darfur is overstretched and underfunded.
The UN Security Council has called for a 20,000-strong peacekeeping force to be deployed in Darfur.
The AU's 7,000 peacekeepers on the ground have made little impact
Under immense international pressure, on 16 November last year, following a meeting in Addis Ababa, the Sudanese agreed to accept what is being called a hybrid force in Darfur - part African Union, part UN.
A three-stage process was mapped out.
In phases one and two the UN would provide back-up to the existing AU force.
Phase three would be the deployment of the joint force.
The Sudanese said they wanted to consult on the size of this ultimate force and the chain of command.
Khartoum has always wanted to minimise the UN influence, preferring to have a force which is more African in nature.
They say a solely UN force would be an act of colonialism, equivalent to an invasion.
'Story of broken hope'
Following a concerted diplomatic effort by Kofi Annan at the end of his time as secretary general, President Bashir sent a letter to Mr Annan on 23 December 2006 agreeing to implement this November agreement.
The Sudanese promised to start on phases one and two, essentially backing up the AU force, but still stalled on the size of the hybrid AU-UN force.
This brings us to Ban Ki-moon.
The new secretary general has called Darfur a story of broken hope.
UN officials were hoping ahead of Mr Ban's meeting with President Bashir that there might be some movement on this key issue - the deployment of the 20,000-strong peacekeeping force
A new secretary general, a new dynamic - perhaps President Bashir will offer something, observed one UN official.
In the event, the hour-and-a-half meeting produced little new.
The discussions were all about phase two, what is known in jargon as the UN heavy support package for the AU troops in Darfur.
But that is only 2,250 peacekeepers.
On the all-important deployment - the 20,000 strong hybrid force- the discussions did not even get off the ground.
Mr Ban is going to send his special envoy for Darfur Jan Eliasson to Sudan in February.
Salim Ahmed Salim, who has the same role for the AU, will go too.
The pair will try to revive the political talks.
Mr Ban said the agreement on phase two would accelerate the deployment of the joint force - the one thing that is really needed to help the people of Darfur.
But months of negotiation lie ahead before that can happen, if it ever does.
Mr Ban told me in an interview at the end of his African trip that he had established trust with President Bashir and hoped he could rely on his promises.
UN officials will be hoping that phrase does not come back to haunt Mr Ban.