United Nations envoys visiting Libya have reached an agreement with the authorities on setting up a humanitarian presence in the capital, Tripoli, Secretary-General Ban Ki-moon said today, while once again calling for an immediate end to the fighting that has taken a heavy toll on civilians.

Nearly half a million people have fled the country in recent weeks since fighting broke out between Government forces and rebels seeking the ouster of Colonel Muammar Al-Qadhafi. In addition, roughly 330,000 people have been internally displaced by the unrest which began earlier this year.

"It is absolutely necessary that Libyan authorities stop fighting, stop killing people," Mr. Ban said during a joint press conference in Budapest with Hungarian President Pál Schmitt, reiterating that the first priority is to secure an immediate and effective ceasefire.

The second priority, he said, is to expand the UN's humanitarian assistance to people in need.

The agreement to set up a humanitarian presence in Tripoli was reached during a visit yesterday to the capital by UN Under-Secretary-General for Humanitarian Affairs Valerie Amos and the Secretary-General's Special Envoy, Abdel Elah al-Khatib. The UN has already established a humanitarian presence in the rebel-held city of Benghazi.

During their visit, Mr. al-Khatib and Ms. Amos met with senior Government officials, including Prime Minister Mahmoud Al-Baghdadi and Foreign Minister Abdel Ati Al-Obeidi.

They reiterated the strong condemnation by the international community of the use of force against civilians and urged the Libyan authorities to stop immediately military attacks against all parts of the country, especially in Misrata where conditions are believed to be very dire, and facilitate the delivery of humanitarian assistance to all those in need.

Mr. Ban warned last week that, under the worst-case scenario, as many as 3.6 million people could eventually require humanitarian assistance, stressing the need to mobilize all means at the disposal of the international community, including military, to get aid to those who need it.

The UN and its partners have appealed for $310 million to provide vital humanitarian assistance to those affected by the crisis in Libya. So far it has received 41 per cent of the needed funding.

The fighting in Libya started out as protests against the Qadhafi regime, and is part of a broader pro-democracy movement across North Africa and the Middle East that has led to the downfall of long-standing regimes in Tunisia and Egypt.