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President Obama plans to call for a “pause” Tuesday night in the push for a congressional vote on military action in Syria, senior administration officials told Fox News, as the president waits to see if an emerging diplomatic option can work.

The early details of the president’s national address show he is continuing to back off his “red line” threat to take military action against President Bashar Assad's regime for its use of chemical weapons. Though his Secretary of State, John Kerry, seemed to push for a congressional vote during testimony on Capitol Hill earlier in the day, officials said Obama is now hitting “pause” on that process.

The pause comes as Kerry plans to meet with his Russian counterpart in Geneva on Thursday to discuss a proposal to have Syria turn over its chemical weapons stockpile to international control.

The administration claims it wants to find out quickly whether this proposal is serious.

Administration officials clarified that Obama is not canceling the congressional votes; but rather, wants to slow them down. Senate Democratic Leader Harry Reid already has postponed a Wednesday test vote on whether to authorize military force.

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One official described the administration’s current approach as a two-track plan – setting up potential votes for military force on the Hill, while also pursuing the diplomatic track.

Another official said that during Tuesday’s meetings on Capitol Hill Obama “indicated a desire to pursue the diplomatic option that was put forward yesterday by the Russians.”

He said the president said his administration would spend the days ahead “pursuing this diplomatic option with the Russians and our allies at the United Nations” while his administration worked with members of Congress on authorizing language.

Administration officials also claimed the White House has been working on the chemical weapons hand-over idea with the Russians for up to year. According to the officials, Kerry did accidentally let the news out on Monday – when he appeared to make an off-handed comment that Assad could avert a strike by turning over his weapons. Kerry immediately walked back the remark.

The officials said that because Russia then openly agreed to the idea, the president is willing to see if this will work. If not, officials said, the White House will still pursue a military course.

No matter what course the administration takes, the president was being challenged from all sides Tuesday -- with Russia's Vladimir Putin pressuring Obama to drop his call for a military strike and members of the Syrian opposition warning that a newly emerging diplomatic option would only play into Assad's hands.

In Russia, Putin reportedly needled the Obama administration to abandon the military option. Putin said the only way diplomacy can work is if "we hear that the American side and all those who support the United States in this sense reject the use of force," according to Reuters.

But the diplomatic option was running into early obstacles, as an emergency meeting of the U.N. Security Council was suddenly called off, after Russia withdrew its request.

And members of the Syrian opposition and others voiced concern that the chemical weapons plan is indeed turning into a "stall" tactic that will allow the Assad regime to escalate conventional warfare on its own people.

Among the most outspoken since the emergence Monday of a potential U.S.-Russia plan has been the Syrian Coalition -- a leader in the nearly three-year-long effort to oust Assad.

"It is vital to remember that the Assad regime, notwithstanding its use of chemical weapons, continues to use all kinds of conventional weapons against innocent women and children," said the group, formally known as the National Coalition of Syrian Revolution and Opposition Forces. "The Assad regime, which has butchered people with knives and burnt them alive, has exhausted all time limits over the past two-and-a-half years."

More than 100,000 Syrians have been killed in the civil war, including an estimated 1,400 in the sarin-gas attack last month that prompted Obama to conclude on Aug. 31 that the United States should launch a punitive strike and ask for congressional support.

The diplomatic plan appeared to emerge Monday morning in London when Kerry said Assad has a long-shot possibility of avoiding a strike by surrendering the weapons. The plan was promptly endorsed by Russian Foreign Minister Sergey Lavrov, and by Monday night Obama appeared to make the idea part of his evolving foreign policy.

"I welcome the possibility of the development," the president told Fox News. "And John Kerry will be talking to his Russian counterparts. I think we should explore and exhaust all avenues of diplomatic resolution of this. But I think it's important for us to keep the pressure on."

Syria's foreign minister embraced the proposal to turn over chemical weapons, saying Tuesday that Syria would declare its chemical weapons arsenal and sign the chemical weapons convention. Kerry, though, said Syria should "go further."

Arizona Republican Sen. John McCain -- among Capitol Hill's most outspoken supporters of efforts to end the Assad regime -- said Tuesday he was "very skeptical" about the proposed diplomatic solution, considering Assad had refused to acknowledge having chemical weapons.

Still, he said Congress should wait on deciding on a military strike until the possibility of a U.N. resolution on controlling Assad's chemical weapons "plays out."

"To not pursue this option would be a mistake," McCain told CBS News before making clear he still thinks the best strategy is military support for Assad opposition forces to help overthrow the government.

Meanwhile, Kansas Republican Rep. Mike Pompeo, a member of the Select Intelligence Committee, told FoxNews.com LIVE's "Power Play" on Tuesday the United States should still strike because the Syrian uprising is a national security concern.

"I don't trust the president to execute this plan well," he said. "It's why I wanted to engage. I was over at the White House yesterday. We had a very direct conversation about what the president ought to say tonight. But more importantly, what the president ought to do if he were to engage militarily in Syria. It's not enough to fire a couple missiles."

Many in Congress, though, are against any U.S. military action in Syria. Senate Republican Leader Mitch McConnell on Tuesday joined those opposing a strike. It's not clear whether Congress will take up a resolution to authorize the use of force.

Earlier in the day, House Democratic Leader Nancy Pelosi claimed there was no need for a congressional vote.

"It is not necessary for Congress to give the president this authority," Pelosi said. "We are grateful that he has asked for it but if he sees an opportunity we don't want the Russians to think that his leverage is diminished because of a vote (that) may or may not succeed within the Congress."

The push-back from Washington and Moscow poses a challenge for Obama, as he finds himself caught between two very different paths on Syria -- a missile strike that potentially drags the U.S. into a bloody civil war, and a diplomatic solution that would likely do little to end that war.

The momentum, at least temporarily, appeared to be running in favor of the diplomatic course.

On Capitol Hill, a bipartisan group of eight senators started writing an alternative resolution that would call on the United Nations to state that Syria used chemical weapons and require a U.N. team to remove the chemical weapons from Syria within a specific time period, possibly 60 days. If that can't be done, then Obama would have the authority to launch military strikes, congressional aides said.

Fox News’ Ed Henry and The Associated Press contributed to this report.