Obama vows air power against IS 'wherever they exist'

Washington (AFP) - President Barack Obama will tell Americans in a prime time address Wednesday that he will go after Islamic State with air strikes "wherever they exist," in clear sign he will attack the jihadists inside Syria.

According to excerpts of his speech released by the White House, Obama will also pledge to aid "partner forces" on the ground in Syria and Iraq but vow no US combat troops will fight on foreign soil.