The United States is poised to send spy planes into Syria to track Islamic State jihadists whose advances have sparked international concern and American air strikes in neighbouring Iraq.
A US official confirmed the plans after Syria said on Monday it was willing to work with the international community, including Washington, to tackle extremist fighters.
But American officials said they did not plan to ask Damascus for permission for the flights, despite Syrian insistence that any military action on its soil must be coordinated in advance.
However, sources yesterday told AFP that the United States has begun reconnaissance flights over Syria and is sharing intelligence about jihadist deployments with Damascus through Iraqi and Russian channels.
International concern about IS has been rising after a lightning offensive by the group through parts of Iraq and a string of brutal abuses, including the murder of US journalist James Foley.
The United Nations has accused IS and affiliated groups in Iraq of acts that could amount to crimes against humanity.
On Monday, Damascus said for the first time that it was willing to work with the international community, including the United States and Britain, to tackle IS and Al-Qaeda's Syrian affiliate Al-Nusra Front.
But Foreign Minister Walid Muallem also made it clear that Syria would not accept unilateral military strikes by the United States or any other country. Muallem said Syria was seeking cooperation within an international or regional coalition, or at the bilateral level within the framework of a recent UN Security Council resolution targeting IS and Al-Nusra.
Yesterday, a security source in Damascus reiterated Syrian insistence on coordination after the US comments about possible surveillance.
"Any entrance into Syrian airspace without coordination would be considered an act of aggression," the source told AFP.
The White House says no decision has been taken on whether to carry out air strikes in Syria.
There have been few signs that the international community is willing to work publicly with President Bashar al-Assad's regime, which has been engaged in a brutal effort to put down an uprising that began in March 2011.
Meanwhile, Syrian war planes launched at least 12 raids using precision rockets against IS positions in Deir Ezzor yesterday, according to the Britain-based Syrian Observatory for Human Rights NGO.