Ms. Migiro will be joined in the Portuguese capital by the UN High Representative for Least Developed Countries, Landlocked Countries and Small Island Developing States Cheick Sidi Diarra, Assistant Secretary-General for Peacekeeping Operations Edmond Mulet and Deputy Chef de Cabinet Kim Won-Soo.

Mr. Mulet and Mr. Kim are scheduled to meet with the Sudanese delegation attending the summit on issues relating to the deployment of the hybrid force, known as UNAMID, to try to quell the fighting between rebels, Government forces and allied militias that has left at least 200,000 people dead and more than 2.2 million others displaced since 2003.

Secretary-General Ban Ki-moon told reporters today that the UN officials will be holding the meetings on the sidelines of the summit to try to resolve the issue of the composition of UNAMID and other issues concerning its deployment.

“We must absolutely have an effective, robust force,” Mr. Ban said. “Without it, there can be no security, nor credible progress in the peace talks. Rebel leaders will simply not join the process without an effective peacekeeping force in place.”

UNAMID is due to take over from the existing but under-resourced AU mission (known as AMIS) by the start of next month, but it lacks offers for crucial force units and the Sudanese Government has raised a series of objections and obstacles.

The mission is short of one heavy and one medium transport unit, three military utility aviation units and one light helicopter unit, while an earlier pledge for one reconnaissance company has been withdrawn.

Mr. Ban said that, despite bilateral talks in person or by telephone with “all possible potential” contributor countries, “I have not been able to get even one single helicopter commitment. We need, at this time, 24 helicopters – three tactical helicopter [units] and one light tactical helicopter unit.”

Acknowledging that many potential contributing countries are overstretched in their critical military assets, he warned that nevertheless “the entire mission is at risk” from the lack of key capabilities.

The Secretary-General has written to Security Council President, Ambassador Marcello Spatafora of Italy, to voice his “grave concern with regard to the shortage of critical assets” and to urge Council members to “exercise their influence so as to transform international concern for the situation in Darfur into the tangible provision of the 24 helicopters that could make such a critical difference to the people of Darfur.”

Khartoum is also yet to approve units for the force, which is supposed to be predominantly African, from Thailand, Nepal and Scandinavia, and it has also not facilitated the acquisition of land and flight operations rights for UN aircraft, impeding the ability of UNAMID to carry out its mandate.

Stating he will write a letter to Sudanese President Omar al-Bashir on the issue, Mr. Ban warned: “Without mobility and transportation, it will be extremely difficult for us to deploy our forces. And even [if] they are deployed, without effective, efficient, mobility capacity, we will not be able to protect civilians and even our own soldiers.”

The UN chief also noted that his Special Envoy on Darfur, Jan Eliasson, is considering holding a major meeting among the region’s rebel movements to help them find a common negotiating position and team for planned direct talks in Sirte, Libya, between the Government and the rebels to solve the conflict.

Meanwhile, Choi Young-jin, the Secretary-General’s Special Representative for Côte d’Ivoire, will also be attending the Lisbon gathering to participate in a separate mini-summit on the West African nation’s current problems and challenges.