Obama approval for spy flights over Syria could pave way for air strikes on militants

While the White House says President Obama has not authorised military action inside Syria, additional intelligence on the militants would probably be necessary before he could take that step. Pentagon officials have been drafting potential options for the president, including air strikes.

The source who confirmed the decision was not authorised to discuss Mr Obama’s decision publicly and insisted on anonymity.

The US began launching strikes against the IS inside Iraq earlier this month, with Mr Obama citing the threat to Americans in the country and a humanitarian crisis in the north as his rationale.

Pentagon chiefs have said the only way the threat from the militants can be fully eliminated is to go after the group inside neighbouring Syria as well.

But Syria warned the United States on Monday that while it was ready to help confront the rising IS threat, carrying out air strikes without the consent of Damascus would be considered an aggression.

Mr Obama has long resisted taking military action in Syria, a step that would plunge the US into a country ravaged by an intractable civil war. However, the president’s calculus appears to have shifted since the Islamic State announced last week that it had murdered American journalist James Foley, who was held hostage in Syria.

The group is also threatening to kill other US citizens being held by the extremists in Syria.

White House spokesman Josh Earnest said Mr Obama demonstrated his willingness to order military action when necessary to protect American citizens.

“That is true without regard to international boundaries,” he said.

The White House would not comment on Mr Obama’s decision to authorise surveillance flights over Syria.

The US had already stepped up its air surveillance of the Islamic State inside Iraq earlier this year as Mr Obama began considering the prospect of air strikes there. The administration has already run some surveillance missions over Syria.