Syria strike test vote put on hold as Obama backs off 'red line'

President Obama will address the nation Tuesday night to discuss the ongoing crisis in Syria, with the debate in Congress over a possible military strike effectively on hold as the president backs away from the "red line" and opens the door to a "diplomatic track."

Senate Majority Leader Harry Reid has postponed a test vote originally teed up for Wednesday. That decision came as the president said in an interview with Fox News that he's open to negotiations on an alternative plan that could avert a military strike.

Reid cited "international discussions" in postponing the vote to advance debate on the resolution authorizing the use of force against Syrian President Bashar al-Assad's government. Reid said it was not important to, "see how fast we can do this," but rather "how well we can do this."

The possible breakthrough pertains to a proposal, floated by Secretary of State John Kerry and then formally put forward by the Russians, to have the Assad regime turn over its chemical weapons to international control. Obama, in an interview with Fox News on Monday, opened the door to pursuing that option.

"We will pursue this diplomatic track," Obama told Fox News. "I fervently hope that this can be resolved in a non-military way."

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    The president, while saying his advisers would "run to ground" that proposal, indicated he still wants Congress to debate a resolution to authorize a strike against Syria. "I think it is important for us not to let the pedal off the metal when it comes to making sure they understand we mean what we say," Obama said.

    But the president's decision to pursue the diplomatic track is a departure from his decision more than a week ago to pursue a military strike. And it could bring the temperature down a notch in the ongoing stand-off between his administration and the Assad government.

    The president's comments come after a proposal to have the Syrian government relinquish control of its stockpile quickly caught fire in the international community and in Washington.

    Kerry touched off the discussion with an off-hand remark that Syria could only avert military action if it turned over its weapons within a week.

    Kerry and his aides afterward claimed the secretary was merely making a "rhetorical" point. But Russia's foreign minister formally proposed the idea to Syria, and the Assad government said it welcomed the plan.

    As the United Nations secretary-general and several U.S. allies gravitated toward the proposal, the Obama administration conceded that it would seriously consider it.

    Obama went further in his interview with Fox News.

    "I welcome the possibility of the development," he said. "We should explore and exhaust all avenues of diplomatic resolution to this."

    He said the U.S. should be able to get a "fairly rapid sense" of how serious the proposal is. "We are going to be immediately talking to the Russians and looking for some actual language they might be proposing," he said.

    But Obama said it's important to "keep the pressure on." Roughly quoting the late President Ronald Reagan, he said: "It's not enough just to trust. I think we're going to have to verify."

    The president said the idea of negotiating this kind of solution is "something that is not new."

    The president also brushed off comments made earlier by Bashar Assad in which he threatened that there could be "repercussions" if the U.S. attacks.

    Assad's military capabilities are "not significant relative to the U.S. military," Obama said.

    The interview comes as Obama prepares to address the nation from the White House on Tuesday night -- as national polling shows Americans are increasingly opposed to U.S. military action in that country's civil war.

    A new Fox News Poll shows that public disapproval of Obama's handling of Syria has jumped from 40 percent to 60 percent. It also found just 36 percent favor using force to punish Syria for using chemical weapons; 61 percent oppose taking that step.

    "Right now, the American people are not persuaded," Obama acknowledged. "Right now, members of Congress who are just getting back still have questions."

    With the proposal so unpopular in the polls, Obama is having a difficult time selling the idea of a strike to Congress. A Senate test vote could still be held later this week, but the White House is struggling to corral the 60 votes that likely will be necessary to advance it.

    The administration faces an even tougher time in the Republican-controlled House.

    Obama stressed in the interview that the situation in Syria is "difficult," but the U.S. was looking at taking action because chemical weapons -- which the administration accuses the Assad regime of using -- are "indiscriminate." But he also said he understands Americans' skepticism over U.S. involvement.

    "The American people are right not to want to have us entangled in a sectarian civil war inside of Syria," he said.

    The Associated Press contributed to this report.