Islamic State
A resident of Tabqa city touring the streets on a motorcycle waves an Islamist flag in celebration after Islamic State militants took over Tabqa air base, in nearby Raqqa city Reuters

US President Barack Obama has formally authorised surveillance flights over Syria, bringing airstrikes against Islamic State (formerly known as Isis) militants a step closer.

Although Washington has cleared the reconnaissance flights, the Obama administration is yet to decide on approving airstrikes on Syrian soil, despite positive signs from the Damascus regime over possible cooperation.

According to multiple media reports citing top Obama administration officials, US spy drones and flights are already in Syrian airspace studying key targets of the Sunni Islamists, who have established a caliphate spanning Iraq and Syria.

The White House has, however, said the president is yet to take a call on military action in Syria.

The Syrian regime, led by President Bashar al-Assad, has signalled that they would cooperate with foreign forces if necessary to fight the Islamic State of Iraq and the Levant (Isis) extremists.

"Syria is ready for cooperation and coordination at the regional and international level to fight terrorism and implement UN Security Council resolution 2170," foreign minister Walid al-Moallem told a press briefing in Damascus.

When asked if the Assad administration would lend a hand to the Western forces, he said: "They are welcome".

The Free Syrian Army (FSA), the umbrella group of anti-Assad rebels fighting against the regime for the past three years, has said the US's latest actions are insufficient to defeat the Sunni militants.

"Airstrikes against Isis inside Syria will not be helpful. Airstrikes will not get rid of Isis. Airstrikes are like just tickling Isis," a spokesperson for the FSA told the Daily Beast.

"Isis is not a real state that you can attack and destroy; they are thugs who are spread all over the east of Syria in the desert. And when they are in the cities, they are using civilian buildings. So airstrikes will not be enough to get rid of these terrorists and at the same time, they might hit civilians. That's the problem."