Sudan has informed the UN chief of the "immediate" end of the United Nations political mission in the war-torn country, according to a letter circulated in the Security Council.In an official letter in Arabic dated Thursday, accompanied by an English version from the Sudanese ambassador to the UN, Foreign Minister Ali Elsadig Ali informed Antonio Guterres of "the decision of the government of Sudan to terminate the United Nations Integrated Transition Assistance Mission in Sudan (UNITAMS) with i