Obama said he will not hesitate to conduct air strikes in Syria as he expands the US fight to "degrade and ultimately destroy" the Islamic State.
"We will hunt down terrorists who threaten our country, wherever they are," Obama said in a rare evening address to the American people from the White House late Wednesday. "That means I will not hesitate to take action against ISIL in Syria, as well as Iraq. This is a core principle of my presidency: if you threaten America, you will find no safe haven.
"ISIL is one of the variants used to refer to Islamic State. The US will step up strikes in Iraq beyond the existing mission that is focused on protecting US interests in the region and providing humanitarian aid, he said. Obama outlined no timeline for an expansion of the US operation, nor did he say how long the mission would last, but Secretary of Defence Chuck Hagel said the military was prepared to act. Secretary of State John Kerry has indicated this week the effort could take months, or even years.
Decisions about expanded air strikes in Syria "will be made at a prudent time as we continue to prosecute our comprehensive strategy against these ISIL terrorists," a senior defence official said.
Obama also aims to increase aid to the moderate Syrian opposition in their fight against the Islamic State and will ask Congress to authorize funding to equip and train the rebels.
Obama stressed the Islamic State poses a growing threat, not just to Iraq and Syria, but also to the rest of the world. "While we have not yet detected specific plotting against our homeland, ISIL leaders have threatened America and our allies," he said. He noted by name the two American journalists who were filmed while being brutally beheaded by Islamic State in Syria.
Obama pointed to intelligence that thousands of foreign fighters, including Europeans and Americans, have joined the group in Iraq and Syria and could carry out attacks in the West. He plans to chair a meeting of the UN Security Council on the threat of foreign fighters on the sidelines of the UN General Assembly in New York later this month. Obama stressed that no US ground combat troops will be sent back into Iraq or into neighbouring Syria, instead relying on US air strikes and regional forces.