March 7 2005 -- The United Nations Security Council must act immediately to avoid a worsening of the humanitarian catastrophe in Darfur. Action is needed simultaneously on several fronts: security, relief, accountability for past crimes and peace talks. Most of all, the Security Council resolution expected in the next few days should reflect the urgent need for a more robust international security presence in Darfur. The council should not pretend that the African Union can resolve the situation alone while the rest of the international community offers only encouragement.

My mandate requires me to alert the UN secretary-general (and through him, the Security Council) to massive violations of international humanitarian law and human rights that could degenerate into genocide. The position is meant to avoid a recurrence of the collective failure to prevent genocide in Rwanda and Srebrenica.

By July 2004, when I was appointed, news of the humanitarian crisis and widespread suffering in Darfur had been on the international agenda for months. In September 2004, at the request of Kofi Annan, the secretary- general, I travelled to Darfur with Louise Arbour, the UN high commissioner for human rights, to assess the situation. Based on our findings, we recommended to the Security Council the deployment of an international police force. We also insisted on breaking the cycle of impunity in which the guilty go unpunished, and increasing the presence of relief workers and human rights monitors. But, five months later, the situation has become even more dangerous, with more than 2m civilians at risk.

To protect civilians, urgent measures are required, such as strengthening the African Union Mission in Sudan, internationally enforced sanctions against those responsible for grave violations and steps to ensure respect for no-fly arrangements.

More than anything, we need a substantial and rapid increase in the international presence in Darfur, including troops, civilian police and a strong protection mandate. The only measure that in the short and medium terms could improve the security situation in Darfur is the deployment of a force of 10,000 - roughly the same size as that being considered for the implementation of the Sudanese North-South peace agreements in a part of the country that is mostly at peace - including a sizeable civilian police component.

Since their deployment in Darfur last year, troops of the African Union Mission in Sudan have performed an excellent job under difficult conditions. I have seen how their presence has been a big deterrent against attacks. But the deployment of troops and police has lagged behind the AU's authorised ceiling of 3,320 - which in itself is too low.

Large swaths of Darfur remain inaccessible to international humanitarian aid, leaving hundreds of thousands of Sudanese at risk of hunger and disease. The World Food Programme estimates that, by the middle of the year, up to 2.8m people may go hungry. The humanitarian community is ready to assist, but it can do so effectively only if security conditions improve.

Without justice there can be no peace. The perpetrators of abuses must be prosecuted. The report of the UN's international commission of inquiry, made public on January 25, documents in horrific detail war crimes and crimes against humanity. It recommends that the Security Council refer the situation in Darfur to the International Criminal Court. The ICC offers the quickest, most effective way to initiate judicial proceedings against those responsible for war crimes and crimes against humanity in Darfur. Holding human rights violators accountable is a strong deterrent and thus constitutes a protective measure. Effective prosecution also depends, however, on security and support on the ground to allow for proper investigations and to protect victims and witnesses.

The AU-sponsored Abuja process is the setting for talks aimed at a lasting peace in Darfur, but the government and rebels have not bargained in good faith. The UN should lend its full support to the AU's mediation and make clear its expectation that the parties must reach an early political solution.

Protective measures, accountability, targeted sanctions and measures to halt aerial bombing and to promote the peace talks are all essential to a comprehensive approach that should be acted on without delay. The people of Darfur depend on it.