President Barack Obama has come under fire from his opponents in Washington as the US launched air strikes against militants from the Islamic State of Iraq and the Levant (Isis) in Iraq.
ongressional Republicans are broadly in favour of military action in the region, but several have criticised the President's strategy, saying it does not go far enough.
The senator and former Republican presidential nominee John McCain said the US should conduct strikes not only against Isis in Iraq, but also against the group's strongholds in neighbouring Syria.
"This is turning into – as we predicted for a long time – a regional conflict which does pose a threat to the security of the United States of America," Mr McCain told CNN, describing the Obama administration's response to the crisis as "very, very ineffective, to say the least".
The Republican congressman Peter King called Mr Obama "weak" for relying on air strikes conducted by warplanes and drones while refusing to send US ground troops into the region.
Appearing on NBC, Mr King said: "We should take nothing off the table."
The South Carolina senator Lindsey Graham told Fox News he feared Isis- inspired attacks on US soil. "If [Mr Obama] does not go on the offensive against Isis, Isil, whatever you guys want to call it, they are coming here," Mr Graham said. "And if we do get attacked, then he will have committed a blunder for the ages."
Others in Washington were more circumspect. The Democrat senator Richard Durbin told NBC that the US should help to prevent genocide in Iraq, but the responsibility for solving the crisis ultimately fell to the Iraqi government. "Only Iraq can save Iraq," Mr Durbin said, adding that there was little appetite in Congress for further military intervention.
"Escalating it is not on the cards," he said.
A Wall Street Journal-NBC poll found last week that 60% of Americans disapprove of the President's handling of foreign policy, while a July survey by Pew found that 55% felt the US had no responsibility to tackle the violence in Iraq.