The United States and Turkey are stepping up planning to deal with emergency scenarios that may arise in Syria, including the possible use of chemical weapons, as fighting between government troops and rebels intensifies.

Senior diplomatic, military and intelligence officials from the U.S. and Turkey met in Istanbul on Thursday to go over detailed operational plans for "the full range of contingencies," the State Department said. Officials said the U.S. is positioning stocks of bio-hazard gear in the region as part of the planning for an international response if chemical weapons are used.

The steps are being taking "in case we confront a situation where (Syrian President Bashar) Assad makes a terrible and horrific choice." State Department spokeswoman Victoria Nuland told reporters.

Thursday's meeting comes on the heels of President Barack Obama's statement that the use or movement of Syria's chemical weapons would be a "red line" for the United States to consider military intervention in the situation.

In addition to laying out a response to the potential use of chemical weapons by Assad's regime, the officials focused on how to help secure them and other advanced or sophisticated armaments once he is out of power, Nuland said.

"When that day comes when the Assad regime falls and we move into transitional government, the international community will want to offer the Syrian people support for managing and disposing of some of the most dangerous weapons of the Assad regime," she said.

The officials also focused on short-term aid for refugees fleeing the fighting and how to assist whatever government that follows Assad in maintaining law and order, rebuilding the economy, restoring public services and repairing infrastructure destroyed in the fighting.

"Historically, various levels of support have been requested for public safety, public security, for restructuring the military," Nuland said. "We need to be ready and available with a menu of options."

Thursday's meeting was the first of a new U.S.-Turkish working group aimed at coordinating Syria policy that was set up earlier this month by Secretary of State Hillary Rodham Clinton and Turkish Foreign Minister Ahmet Davutoglu.