(ABC News) -- President Obama warned Americans today to prepare for a prolonged military fight over the skies of Iraq, striking a defensive and defiant tone over the need to reengage in a war he tried ending nearly three years ago.
"I don't think we're going to solve this problem in weeks," Obama said, speaking at the White House moments before leaving for a summer vacation on Martha's Vineyard. "This is going to be a long-term project."
The president renewed his promise to keep American ground forces out of the conflict, declaring: "We should have learned a lesson from our long and immensely costly incursion in Iraq."
But he forcefully pushed back against criticism that his decision to withdraw combat troops in 2012 contributed to Iraq's latest collapse.
"That entire analysis is bogus and is wrong," Obama said, his voice rising as he stood on the South Lawn of the White House. "But it gets frequently peddled around here by folks who oftentimes are trying to defend previous policies that they themselves made."
The stabilization of a new and inclusive Iraqi government, Obama said, was central to determining how long the United States would stay engaged in the latest Iraq conflict. He said the U.S. would be a partner in the effort, but could not lead the way.
"Ultimately, only Iraqis can ensure the security and stability of Iraq," Obama said. "The United States can't do it for them, but we can and will be partners in that effort."
In his morning address, the president said the back-to-back round of air strikes on Friday "successfully destroyed arms and equipment" that militants from the Islamic State in Iraq and Syria had positioned in their attempt to capture Erbil. Yet he said the humanitarian mission would not be accomplished as swiftly.
Obama said British Prime Minister David Cameron and French President Francois Hollande agreed to join the United States in trying to move the Yazidis from Mount Sinjar, where thousands have fled to find refuge from the militant fighters.
The president said the chief goal of the military campaign was to protect Americans and American interests in Erbil, along with trying to ensure "safe passage" for the Iraqi minorities trapped on the mountain.
"We're not moving our embassy anytime soon," he said. "We are going to maintain vigilance and ensure that our people are safe."
The president spoke expansively on the Iraq mission, taking question after question from reporters. But it was clear that his two-week vacation awaited: Marine One was idling on the South Lawn, ready to take off as soon as he finished speaking.
"I'm ready to not have a suit on for a while," he said.