US President explained that the United States will "conduct a systematic campaign of airstrikes against these [IS] terrorists."
"Working with the Iraqi government we will expand our efforts beyond protecting our own people and humanitarian missions so that we are hitting ISIL targets as Iraqi forces go on offense," Obama added.
Obama also promised to send more US service members to Iraq in order to increase support to the forces, fighting IS on the ground.
"In June I deployed several hundreds of American service members to Iraq, to assess how we can best support Iraqi security forces. Now that those teams have completed their work and Iraqis formed a government we will send an additional 475 service members to Iraq," Obama said, adding that the US forces will not have a combat mission and that they are needed to support Iraqi and Kurdish forces with training, intelligence and equipment.
The Islamic State, also known as the Islamic State of Iraq and Greater Syria (ISIS) or the Islamic State of Iraq and the Levant (ISIL), is a Sunni jihadist group that has been fighting the Syrian government since 2012. In June 2014, the group extended its attacks to northern and western Iraq, declaring a caliphate on the territories under its control later that month.