President Obama said Friday he will address the American people on Tuesday about Syria, a key move in his effort to persuade Congress to back a military strike.
"I will make the best case that I can," he told reporters at the end of the G-20 summit in St. Petersburg, Russia, where he sought global support for force against Syria.
MORE: Obama Meets With Putin Amid Syria Dispute
Obama declined to say whether he would order an attack against Bashar Assad's government even if Congress rejects authorization, saying he did not want to "jump the gun and speculate."
The president said he and his team will "systematically" speak to every member of Congress about plans to target Assad's chemical weapons capability and emphasize that it would be a "limited" operation without American ground troops.
Acknowledging intense opposition in both the House and Senate, Obama said, "I knew this was going to be a heavy lift."
The G-20 summit reflected some global opposition to a strike on Syria, but Obama said an Aug. 21 chemical weapons attack against Syrian rebels requires a strong response.
"There is a growing recognition that the world can't stand idly by," he said.
Obama confirmed he had an unscheduled meeting Friday with one major critic, Russian President Vladimir Putin. Both leaders called the meeting constructive, but Putin again said Obama has not made his case against the Assad government, and that military action would be a mistake.
"We stuck to our guns," Putin told reporters.
While Obama used the G-20 to try and build global support for military action, the president's speech Tuesday is directed at other skeptical audiences: the American public and Congress, which is considering a resolution authorizing force.
Many lawmakers say the resolution faces an uphill battle, particularly in the Republican-run House but also in the Democratic Senate.
Obama said he understands concerns about a "slippery slope" in Syria, and worries that it could escalate into an Iraq-type war.
But the recent chemical attack in Syria is not just a tragedy, but "a threat to global peace and security," he said. He cited international laws against chemical weapons use and said a failure to respond in Syria would only encourage more attacks.
"That's not the world we want to live in," Obama said.
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