US president Barack Obama will tell Americans shortly that America aims to lead what he will call a "broad coalition" in a "steady, relentless effort" to take on and defeat IS.
But, he is expected to tell Americans in a TV address early on Thursday US time, "it will not involve American combat troops fighting on foreign soil." That said, the campaign against IS would seek to take them on in Syria and Iraq and "wherever they exist", Obama was due to say according to briefings given to journalists pr4ior to his address.
Obama said in excerpts of a speech: “This counter-terrorism campaign will be waged through a steady, relentless effort to take out ISIL wherever they exist using our air power and our support for partner forces on the ground,” using an acronym for the militant group.
Obama will seek to reassure Americans that this campaign will not be like recent US interventions in Afghanistan and Iraq.
“I want the American people to understand how this effort will be different from the wars in Iraq and Afghanistan. It will not involve American combat troops fighting on foreign soil,” Obama will tell the nation.
"This counter-terrorism campaign will be waged through a steady, relentless effort to take out ISIL wherever they exist using our air power and our support for partner forces on the ground. This strategy of taking out terrorists who threaten us, while supporting partners on the front lines, is one that we have successfully pursued in Yemen and Somalia for years."
Mr Obama has been heavily criticised in the US since stating recently in response to IS activity, including videoed beheadings, that he had yet to devise a strategy for dealing with IS.
His address seeks to respond to such criticisms and galvanise the US and its allies for what many analysts say they believe will be a long-haul campaign against the Islamic extremists.