US Defense Secretary Ashton Carter has said that the US is to deploy a specialized force to Iraq to build pressure on Islamic State militants.
He said, the operators would carry out raids, free hostages and capture IS leaders.
They would also conduct "unilateral operations" in Syria.
Islamic State conquered large swathes of Iraq and Syria in the summer of 2014.
A US-led coalition of 65 countries is conducting a campaign against the militants in both countries.