WASHINGTON — A year ago, President Barack Obama was barreling toward airstrikes in Syria when he abruptly announced that he first wanted approval from congressional lawmakers. The move threw his policy into confusion and the strikes were eventually scrapped.

Now, as Obama again contemplates military action in Syria, the White House is suggesting it may not be necessary to get a sign-off from Congress. While cautioning that Obama has made no final decisions, officials say there is a difference between last year’s effort to strike Syria’s government in retaliation for chemical weapons use and a bombing campaign against Islamic State militants that is now under consideration.

“The situation a year later is markedly different,” White House spokesman Josh Earnest said when asked whether Obama would again seek congressional authorization. “What we’re talking about now is confronting a terrorist group that has sought safe haven in Syria. This is a group that poses a threat to Americans in the region and could potentially, down the line, pose a broader threat to American interests and our allies around the globe.”

Earlier this month, Obama authorized U.S. airstrikes against Islamic State targets in Iraq. The militants have been moving with ease between Iraq and Syria, effectively blurring the border between the neighboring nations.

Republican Sen. Bob Corker of Tennessee, a frequent critic of the administration’s foreign policy, has said Congress should “certainly” authorize any military action in Syria. Sen. Tim Kaine, a Virginia Democrat and White House ally, has also called for a vote on the president’s broader strategy for going after the Islamic State.

The military launched three more airstrikes in Iraq on Wednesday, bringing the total number of U.S. strikes to 101 since Aug. 8.

While Obama initially resisted going after the Islamic State in their operating base in Syria, his calculus appears to have shifted after the militants announced that they had killed American journalist James Foley. The group is threatening to kill other U.S. hostages, including journalist Steven Sotloff.