The president said U.S. airstrikes, combined with military expertise, would be more effective in defeating the group that calls itself the Islamic State.
In an interview with NPR, the national security adviser said the U.S. will not be drawn into a ground war in Iraq and Syria, even if local forces are insufficient at containing the Sunni militants.
The expected vote on whether to authorize the Obama administration's plan to arm and train moderate fighters comes as the president meets with military officials at U.S. Central Command.
The chairman of the Joint Chiefs of Staff told a Senate panel he supports the president's plan to combat Islamic State militants but that if it proved necessary, he would recommend U.S. ground forces.
The disparities in naming are partly because of translation difficulties, and partly a sign of a propaganda war. The group calls itself the Islamic State; the Obama administration goes with ISIL.
On a weekend that saw extremist group the Islamic State release a video showing the murder of a Western hostage, support for a coalition to fight the group is building.