US President Barack Obama has told Congressional leaders he does not need lawmakers’ approval for any action in Iraq, the top Senate Republican says.
Senator Mitch McConnell was speaking after a meeting between the president and senior members of Congress.
Iraq has asked for US air strikes against advancing jihadist militants, who have seized key cities and towns.
But correspondents say any decision on military support from Washington could hinge on political changes in Iraq.
US Vice-President Joe Biden discussed possible “additional measures” that could help “roll back the terrorists’ advances” with Iraqi Prime Minister Nouri Maliki on Wednesday, but also the need for national unity.
The Obama administration has shown signs of frustration with Mr Maliki – a Shia Muslim who has long been accused of discriminating against the Sunni Arab minority community and monopolising power.
Defence Secretary Chuck Hagel told a congressional hearing: “This current government in Iraq has never fulfilled the commitments it made to bring a unity government together with the Sunnis, the Kurds, and the Shia.”
Mr Obama met Congressional leaders at the White House on Wednesday to discuss the US response to recent advances by the Islamic State in Iraq and the Levant (ISIS).
Speaking afterwards, Mr McConnell said the president had “indicated he didn’t feel he had any need for authority from us for steps that he might take”.
Correspondents say the White House has so far avoided the thorny question as to whether it needs Congressional authority for any military action in Iraq.
