House Speaker John Boehner issued a statement in response to the operations in Iraq, calling Obama's authorization of airstrikes "appropriate," but adding that he is "dismayed by the ongoing absence of a strategy for countering the grave threat ISIS poses to the region."
"Vital national interests are at stake, yet the White House has remained disengaged despite warnings from Iraqi leaders, Congress, and even members of its own administration," Boehner said in the statement. "Such parochial thinking only emboldens the enemy and squanders the sacrifices Americans have made."
In a Thursday night address, President Barack Obama said the U.S. had begun dropping humanitarian aid into Iraq, and that it would conduct military airstrikes if U.S. personnel or assets were threatened.
The president also said in his address that any airstrikes will aim to prevent the "genocide" of Iraq's Yazidi sect at the hands of Sunni fighters from ISIS.
Read More Obama authorizes targeted airstrikes in Iraq
Combatants from ISIS, an al-Qaeda offshoot bent on establishing a caliphate—a wholly Islamic state —and eradicating unbelievers, have swept through northern Iraq since June. Their advance has dramatically accelerated in the past week when they routed Kurdish troops near the Kurdish autonomous region in the north.
"Earlier this week, one Iraqi in the area cried to the world, 'There is no one coming to help'," Obama said on Thursday. "Well, today America is coming to help."
Stock futures were still higher after the airstrike news, though they did give back some gains.
—By CNBC. Reuters contributed to this report.