(Updates with quotes, context)
By Steve Holland and Patricia Zengerle
WASHINGTON, Aug 28 (Reuters) - President Barack Obama said on Thursday that he has not yet developed a broad strategy for confronting Islamic State in an acknowledgement that he has not decided whether to launch air strikes against the militant group in Syria.
"We don't have a strategy yet," Obama told a White House news conference ahead of meeting top national security advisers in the Situation Room about how to proceed against Islamic State.
Obama's decision to begin U.S. surveillance flights over Syria earlier this week prompted speculation that he was on the brink of expanding the fight against Islamic State from Iraq into Syria, prompting criticism from some lawmakers who worry they have not been properly consulted.
There has been a growing call from both Republicans and Obama's fellow Democrats in Congress for lawmakers to vote on whether the United States should broaden its action against the Islamic State.
Obama, who shied away from launching airstrikes in Syria a year ago to punish Syrian President Bashir al-Assad for use of chemical weapons against his own people, has been reticent about getting involved in Syria's civil war, where he believes there are few good options for the United States to pursue.
Public anger at the beheading of American journalist James Foley, however, has led him to consider hitting Islamic State targets in Syria. So far the U.S. campaign against the group has been limited to striking the group's forces in Iraq but not taking on Islamic State's primary stronghold in Syria.
Obama said he has asked Defense Secretary Chuck Hagel to prepare options for confronting Islamic State and said Secretary of State John Kerry will travel to the region to help put together an anti-Islamic State coalition.
White House spokesman Josh Earnest said after the news conference that when Obama said "we don't have a strategy yet" for Islamic State he was referring to military options still being developed for Syria.
Obama wants a comprehensive strategy for Islamic State that is not limited to military action but also includes encouraging a unity government in Baghdad between Shi'ites and Sunnis who have engaged in sectarian battles and supporting moderate Sunni rebels in Syria.
"My priority at this point is to make sure that the gains that ISIL (Islamic State) made in Iraq are rolled back and that Iraq has the opportunity to govern itself effectively and secure itself," he said.
He said the options he had requested from military planners at the Pentagon focused primarily on making sure that Islamic State is "not overrunning Iraq."
Congressional concerns have been increasing about a potential military strike in Syria.
In the House of Representatives, three members - Democrats James McGovern of Massachusetts and Barbara Lee of California as well as Republican Walter Jones of North Carolina - asked Speaker John Boehner in a letter that Congress debate and vote on any authorization to use military force when the House is in session during the week of Sept. 8.
Kentucky Senator Mitch McConnell, the top Republican in the Senate, said he thought Obama would have "significant congressional support" if he provides a strategic plan to protect the United States and its allies from the Sunni militants.
Obama promised he would consult with Congress, but unlike a year ago when strikes were considered against Syria, he did not vow to seek a specific congressional authorization.
"I don't want to put the cart before the horse," he said. He said news reports have suggested he is on the brink of an elaborate strategy for defeating the group without consulting Congress.
"That's not what's going to happen," he said. (Additional reporting by Roberta Rampton and Mark Felsenthal; Editing by Sandra Maler and Eric Walsh)