New Delhi, Sep 11 (ANI): In a campaign against the Islamic State militant group, US President Obama told Americans he had authorized US airstrikes for the first time in Syria and more attacks in Iraq. Obama said it will take time to eradicate Islamic State extremists but is offering no timetable for how long the United States will conduct airstrikes against the group in Iraq and Syria. The president said the military campaign will not involve American combat troops on the ground. It's a shift for Obama, who has been reluctant to increase the US military footprint in the region. And who, three years ago, pulled out the last combat troops from Iraq.