Updated

Secretary of State John Kerry's seemingly casual proposal for the Assad regime to turn over its chemical weapons has within 24 hours become the de facto policy of the Obama administration, and is now being heralded by Kerry as the "ideal way" to defuse the stand-off between the United States and Syria.

But a look at the administration's statements shows that the plan has undergone an incredible evolution.

Just one day ago, Kerry mentioned the idea in response to a question about what Bashar Assad could do to avert an attack

"He could turn over every single bit of his chemical weapons to the international community in the next week," Kerry said. He then immediately splashed water on the notion: "But he isn't about to do it, and it can't be done, obviously."

His aides swiftly set about to walking the remark back, describing Kerry's comment as merely a "rhetorical argument."

Yet on Tuesday morning -- after the Russians had co-opted the idea and formally presented it to the Syrian government -- Kerry was claiming full credit for the plan during testimony before the House Armed Services Committee.

"Yesterday, we challenged the regime to turn (its chemical weapons) over to the secure control of the international community so that they can be destroyed," Kerry said.

He added, "Nothing focuses the mind like the prospect of a hanging," claiming the "credible threat" of military action is what brought the Assad regime to its knees.

Several U.S. officials echoed Kerry on that point, claiming Assad would not be willing to negotiate if it weren't for the imminent threat of a U.S. missile strike.

But the notion that Kerry had deliberately opened the door to the chemical weapons turn-over plan raised doubts.

"We still don't know exactly how this plan came about," Fox News contributor Byron York said.

Whatever the origin of the plan, it was taking off on Tuesday even as Kerry and others pressed Congress to continue debating a resolution authorizing military force, and even as President Obama prepared to address the nation Tuesday night.

After the Russian government proposed having the Assad regime turn over its chemical weapons, the Syrian foreign minister said his government would accept the plan.

U.S. officials continue to voice doubts about the idea, but are opening the door to pursuing the "diplomatic track."

"We're waiting for that proposal, but we're not waiting for long," Kerry said Tuesday.

He said Obama would take a "hard look" at the plan.

"It has to be swift. It has to be real. It has to be verifiable," Kerry said.

The deliberation comes as Congress considers a resolution to authorize the use of force. Senate Democratic Leader Harry Reid postponed a test vote originally expected for Wednesday, but Congress could still consider it later in the week.

Kerry urged lawmakers to keep debating, claiming that Washington needs to keep the pressure on Syria while the new proposal is considered.