Syria says it will cease fighting Thursday The UN-Arab league envoy Kofi Annan listens at joint press conference with Iranian foreign minister Ali-Akbar Salehi in Tehran, Iran on April 11,2012. Annan is in Tehran for talks with senior Iranian officials about the conflict in Syria. UPI/Maryam Rahmanian NEW YORK, April 11 (UPI) -- U.N.-Arab League envoy Kofi Annan Wednesday said Syria has told him it will "cease all military fighting" Thursday morning. Annan received a letter from the Syrian minister of foreign affairs less than 24 hours before the agreed upon date to begin a cease-fire with opponents of the regime of President Bashar Assad. The letter said government forces would "cease all military fighting throughout Syrian territory as of 6 a.m. [Damascus time] tomorrow, Thursday, 12 April 2012," Annan spokesman Ahmed Fawzi said. However, the letter said Syria reserved "the right to respond proportionately to any attacks carried out by armed terrorist groups against civilians, government forces or public and private property." The United Nations estimates more than 8,000 people, mostly civilians, have been killed and tens of thousands displaced since protests in Syria began in March 2011. Fawzi said Annan, who visited Damascus last month, would continue to push the Syrian government and the opposition to implement his six-point plan to halt the violence. Annan is to address the U.N. Security Council on Syria Thursday. "We still have time between now and 12 April to stop the violence," Annan said earlier after visiting Syrian refugee camps on the Turkish side of the border with Syria -- an experience he called "heart-wrenching." Annan's six-point plan originally called for Syria to withdraw troops and weapons from populated areas by 6 a.m. local time Tuesday and for all hostilities against Syrian citizens to end by 6 a.m. The Assad government said it would withdraw its troops and abide by a cease-fire only if the opposition fighters, whom it calls terrorists, put down their weapons and if Qatar, Saudi Arabia and Turkey guarantee they will "stop funding and arming terrorist groups."