Barack Obama will begin laying out a strategy this week to defeat Islamic State militants in the Middle East.
One defence analyst said last night: “There is going to be a war, plain and simple.”
The expansion of US operations against the terrorists will fuel fears for Scots aid worker David Haines, who was shown being held captive in an IS video last week, in which American journalist Stephen Sotloff was beheaded.
The American president will meet congressional leaders tomorrow and deliver a speech to the American people on Wednesday – the eve of the 13th anniversary of 9/11, the deadliest terrorist attack on US soil.
The US expanded its operations in the region over the weekend, carrying out air strikes on IS for the first time in western Iraq to defend Iraqi troops at Haditha Dam.
The attack was the first in direct support of the Baghdad government since the launch of Washington’s campaign a month ago.
The Pentagon said US aircraft had carried out air strikes near the dam along the Euphrates River in the Anbar province, where Iraqi troops loyal to the Baghdad government and allied Shia militias have for months been fighting IS.
Mr Obama said yesterday: “I just want the American people to understand the nature of the threat and how we’re going to deal with it and to have confidence that we’ll be able to deal with it.”