ISTANBUL -- Turkey and the United States agreed Saturday to accelerate preparations for the possible fall of Syrian President Bashar Assad, creating a formal bilateral team to help the opposition, providing aid to fleeing refugees, and planning for worst-case outcomes that include a chemical weapons attack.
Secretary of State Hillary Clinton and Turkey's Foreign Minister Ahmet Davutoglu said that with the situation in Syria growing more dire, it was time to share information and planning.
They said a task force with intelligence, military, and political leaders from both countries would be formed immediately to track Syria's present and plan for its future.
Mrs. Clinton, who also announced an additional $5.5 million in humanitarian assistance for refugees, left open the possibility of setting up a no-fly zone, suggesting that the team assigned to perform an "intense analysis" of all options could be a precursor to more direct assistance. But she stopped short of describing specific plans for helping Syria's opposition fighters.
U.S. officials said the United States remained concerned about providing weapons or air support because it could draw a violent response, not just from Syria but also from Russia, Iran, and other allies of Assad.
Hinting at fears of a wider war, Mrs. Clinton said the goal was to hasten the removal of Assad but "not in a way that produces even more death, injury, and destruction."
In Syria on Saturday, gunmen detonated back-to-back roadside bombs and clashed with police in central Damascus in attacks that caused no damage but highlighted the ability of rebels to breach the intense security near Assad's power bases.
In Aleppo, activists said Syrian forces pressed ahead with an offensive to break rebel footholds in the city.
The London-based Syrian Observatory for Human Rights said a helicopter gunship fired missiles at apartment buildings.