President Barack Obama says the US will send 300 military advisers to Iraq to help fight Islamist-led insurgents.
Mr Obama said the US was prepared for “targeted and precise military action, if and when” required, but added that US troops would not fight in Iraq.
He insisted there was “no military solution” and urged the Shia-led Iraqi government to be “inclusive”.
US Secretary of State Kerry is expected to travel to Iraq soon to press for a more representative cabinet.
Iraq has asked the US for air strikes against the Sunni militants – spearheaded by the jihadist Islamic State of Iraq and the Levant (ISIS) – who have made major territorial gains in the past 10 days.
Drawn from America’s special forces, the military advisers will set up joint command centres with the Iraqi military in Baghdad and in the north. But they will also go out into the field.
Senior administration officials have said that they are not at the stage of preparing air strikes, adding that they will be discreet and targeted if they come. They have also indicated that ISIS militants could come under American fire over the border in Syria.
At present the use of American air power is not being made conditional on Prime Minister Nouri Maliki stepping down, but clearly he has lost Washington’s confidence.
US Secretary of State John Kerry is expected to travel to Iraq as part of a wider diplomatic mission to the Middle East and North Africa. His main aim it seems will be to press for the formation of a new more inclusive government.