The United States launched air and missile strikes with Arab allies in Syria for the first time around 8:30 p.m. ET on Monday evening, killing dozens of Islamic State fighters and members of a separate al Qaeda-linked group, and widening its new war in the Middle East.
The attacks finally fulfill the president's weeks of speeches that pledged U.S. action against the Islamic State, a Sunni Muslim group that has seized swathes of Syria and Iraq, and imposed a medieval interpretation of Islam that has included brutal slaughter of locals.
On Tuesday, Obama's outlined plan included increased efforts to "equip and train the Syrian opposition" as well as "cut off ISIL financing, to counter its hateful ideology and to stop the flow of fighters into and out of the region."
"We will not tolerate safe havens for terrorists who threaten our people," he said, adding that last night's attack also targeted a terror organization.
Finally, the president highlighted the bipartisan support for U.S. action.
"That unity sends a powerful message to the world that we will do what's necessary to defend our country," he said. "The overall effort will take time. There will be challenges ahead, but we're going to do what's necessary to take the fight to this terrorist group for the security of the country, and the region, and for the entire world."
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Later in the afternoon, the president is expected to meet with the Arab nations that participated in the Syria strikes last night. In the next few days he is also scheduled to speak with world representatives, including the prime minister of Iraq, at the United Nations.
Reuters contributed to this report.