Diplomacy over Darfur has failed and the international community must now consider sanctions against Sudan to pressure it into accepting UN peacekeepers, the Brussels-based International Crisis Group (ICG) said in a report published on Thursday.

"Patient diplomacy and trust in Khartoum's good faith has been a patent failure," they reported.

"The international community has little choice but to pursue an action plan based primarily on economic, legal and more limited military measures."

Sudan has resisted international pressure to allow around 20,000 UN troops to replace an ill-equipped African Union peace-keeping force of 7,000 in Darfur.

"...It may be possible to persuade the NCP (Sudan's dominant National Congress Party) to alter its policies and consent to the UN mission in Darfur by moving now to targeted sanctions against regime leaders and their business interests," the ICG said.

Some 200,000 people have been killed and up to 2.5 million have been displaced by the three year long conflict. Sudan President Omar Hassan al-Bashir has compared the UN force to a Western invasion and an attempt to recolonise Sudan.

Human rights groups, some diplomats and the UN envoy to Sudan, Jan Pronk, have suggested the international community should focus its efforts on prolonging and strengthening the African Union force.

But ICG said that was "too little too late, given the way the security, human rights and humanitarian situation have steadily deteriorated".

Christian Aid welcomed African Union's (AU) decision last month to extend the mandate of its peacekeeping force in Darfur until the end of the year.

"This is good news for the millions of displaced people in Darfur," said Judith Melby, Christian Aid's Africa specialist. "But it is only a first step. For the force to be truly effective it must receive more troops, more logistical support and a stronger mandate."