Updated

Members of the main opposition groups in Syria have issued their own plan for ending the violence in their country, saying more than 1,200 have been killed since Kofi Annan, the U.N. and Arab League envoy, announced the Syrian regime’s “agreement” to his six-point proposal.

Detailing the opposition's alternative plan exclusively to Fox News, Ammar Abdulhamid, an influential Syrian human rights activist, said Annan’s initiative clearly had “failed.” He also said that, given Syrian President Bashar al Assad’s track record for reneging on such agreements, “there was no reason for anyone to be surprised by the turn of events.”

Backed by the Obama administration, Annan had managed to shore up support from the U.N. Security Council’s 15 members – among them Russia and China, which earlier had vetoed resolutions aimed at reining in the Syrian regime. Central to Annan’s plan was a call for a cease-fire by 6 a.m. this Thursday, Damascus time, with troop withdrawal and other conditions set for its implementation.

But an earlier deadline, which called for Syrian troops to withdraw with their heavy weaponry from all cities, towns and villages ignored by the regime, was not met. Therefore, the hope that a cease-fire will take effect Thursday seems rather remote.

Abdulhamid, who fled Syria in 2005 and has since lived in the United States, told Fox News that members of the main opposition groups, representing all political and religious backgrounds, helped draw up the new six-point plan. He added that he hoped the plan would achieve the goal of stopping the Assad regime’s violence and bringing about the Syrian leader’s ouster.

The plan calls for arming local resistance forces, establishing a safe haven for civilians and providing international aerial support for resistance fighters. It also calls for stepped-up diplomatic pressure on the Assad regime and its supporters, with specific steps taken to encourage defections by top government officials. These steps would include offers of amnesties, with specific start and end dates.

Finally, the plan calls for identifying countries willing to provide future peacekeepers who could be instantly dispatched to liberated territories to ensure stabilization and support ongoing efforts by opposition groups in regard to transition planning.

Click here for the full Syrian opposition plan.

Some analysts think the Obama administration and international allies may be forced to endorse a more aggressive strategy as the only way to stop the ongoing civilian massacres in Syria, even if the Assad regime honors Thursday's deadline for a cease-fire.

“The apparent failure of the Annan plan will return the Syria crisis to the U.N. Security Council, where the U.S. will probably look to ratchet up the pressure in cooperation with the Turks and Arab League," Michael Singh of The Washington Institute, a former senior director for Middle East affairs at the National Security Council, told Fox News. "The real question will be what to do if Russia and China once again block tougher action by the Council.”

Indeed, a letter sent by the Turkish government to the United Nations Security Council on Tuesday urged the council to take “necessary measures to protect the Syrian people,” since the Assad regime had not honored its commitments to Annan’s plan.

Abdulhamid, a member of the Syria Working Group at the Foundation for Defense of Democracies in D.C., said he and his colleagues hope that “leaders of the international community, especially the U.S., begin treating the situation with the needed urgency, before the situation gets any worse.”