The United Nations' top envoy for Iraq has urged the government in Baghdad not to close Camp Ashraf — housing more than 3,000 Iranian dissidents — by the end of this year.

Martin Kobler told the U.N. Security Council Tuesday the world body is working with the Iraqi government to find a satisfactory solution to the plight of the camp's residents. He said the camp is a matter of great concern, but that the situation clearly cannot be fully resolved by the December 31 deadline.

Camp Ashraf is a base of Iran's main armed opposition group, the People's Mojahedin Organization of Iran. The United States, which considers the group a terrorist organization, transferred security of the camp to Iraq in 2009.

Iraq and Iran also consider the group a terrorist organization, but the European Union has removed it from its list. Last month, EU foreign policy chief Catherine Ashton said she would urge the member states to accept residents of the camp.

Iraq has said that after the camp's closure, it will transfer the residents to other locations inside the country until they can be resettled in third countries, or return to Iran under an amnesty. Others may be allowed to stay in Iraq if they qualify for refugee status.

Many of the Camp Ashraf residents have lived in Iraq for decades. Former Iraqi President Saddam Hussein, who fought a long war with Iran in the 1980s, gave the Iranian opposition group safe haven. Its members often launched attacks on Iran from their base in eastern Iraq before Saddam's ouster in 2003.

A raid by Iraqi security forces on Camp Ashraf earlier this year drew international concern for the residents there. U.N. human rights chief Navi Pillay has said the raid killed at least 34 people.

Earlier this year, Baghdad and Tehran signed an agreement to extradite criminals wanted by the two neighbors.