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 co-ordinated in advance.
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 carrying out “ethnic and religious cleansing” 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 “terrorists” including 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.
“Any violation of Syria’s sovereignty would be an act of aggression,” he said.
There would be “no justification” for strikes on Syrian territory “except in coordination with us to fight terrorism”.
Muallem said Syria was seeking co-operation 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.
But it remains unclear whether the international community will be willing to co-operate 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.
Washington has accused Assad’s regime of using chemical weapons against his own people and carrying out other widespread abuses.
International concern about IS has also grown, with Washington beginning air strikes against the group in Iraq on August 8 in a bid to roll back its advances.
US Chairman of the Joint Chiefs of Staff General Martin Dempsey acknowledged after the strikes began that IS could not be defeated in Iraq alone.
“Can they be defeated without addressing that part of the organisation that resides in Syria? The answer is no,” he said.
The White House says that no decision has been taken on whether to carry out air strikes in Syria.
But American aircraft have already entered Syrian airspace covertly at least once, during a failed bid to rescue hostages including Foley, who was later beheaded by IS militants.
Foley’s murder and advances by IS in both Syria and Iraq have heightened fears about the group, which emerged from Al-Qaeda’s one-time Iraqi affiliate but has since parted ways.
UN human rights chief Navi Pillay said Monday that IS and affiliated groups in Iraq were “systematically targeting men, women and children based on their ethnic, religious or sectarian affiliation and are ruthlessly carrying out widespread ethnic and religious cleansing.
“Such persecution would amount to crimes against humanity,” she said in a statement.
On Sunday, IS also cemented its control over an entire province in Syria for the first time, seizing the Tabqa military airport in a bloody battle that killed hundreds of people.
The air base was the last outpost controlled by the Syrian military in Raqa province, which has now become an IS stronghold.
In Iraq, the group has seen its momentum curbed in some areas by Kurdish forces backed by American air strikes, but it still holds significant areas that federal troops are still struggling to regain.
On Tuesday, a car bomb struck a crowded Baghdad intersection away from the frontline fighting, killing at least 10 people in an area where a suicide bomber targeted Shi’ite worshippers the day before, killing 11.