A week ago, Obama said he felt limited strikes in Syria were needed, but added he wanted to ask Congress to authorize the use of military force.
Neither Democratic nor Republican lawmakers have been enthused about the prospect, partly because Americans strongly oppose getting involved in a another Middle Eastern conflict.
A Reuters/Ipsos poll on Tuesday said 56 percent of Americans believed the United States should not intervene, while only 19 percent supported action.
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"I know that the American people are weary after a decade of war, even as the war in Iraq has ended, and the war in Afghanistan is winding down. That's why we're not putting our troops in the middle of somebody else's war," Obama said in his recorded address.
Obama and his top officials plan an intensive lobbying effort on Capitol Hill next week, scheduling meetings with undecided lawmakers.
Obama said failing to respond to the August 21 attack that Washington blames on President Bashar al-Assad's government and that killed hundreds of children and more than 1,400 people in total, would threaten U.S. national security by increasing the chance of future chemical attacks from the Syrian government, terrorist groups, or other nations.
"We are the United States of America. We cannot turn a blind eye to images like the ones we've seen out of Syria," he said.
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