Syrian President Bashar Assad
Syrian President Bashar AssadIsrael news photo: Flash 90

Engineers working for President Bashar Al-Assad’s regime in Syria have begun combining the two chemical precursors needed to weaponize sarin gas, an American official with knowledge of the situation told Wired.com’s Danger Room on Monday.

International observers are now more worried than they’ve even been that the Damascus government could use its nerve agent stockpile to slaughter its own people, the report said.

The U.S. doesn’t know why the Syrian military made the move, which began in the middle of last week and is taking place in central Syria, nor are they sure why the Assad government is transferring some weapons to different locations within the country, as the New York Times reported on Monday.

“Physically, they’ve gotten to the point where they can load it up on a plane and drop it,” the official told Wired.com.

Sarin gas has two main chemical components: isopropanol, popularly known as rubbing alcohol, and methylphosphonyl difluoride. The Assad government has more than 500 metric tons of these precursors, which it ordinarily stores separately, in so-called “binary” form, in order to prevent an accidental release of nerve gas.

Last week, reported Wired.com, that changed. The Syrian military began combining some of the binaries. “They didn’t do it on the whole arsenal, just a modest quantity,” the official said. “We’re not sure what’s the intent.”

Back in July, the Assad regime publicly warned that it might use its chemical weapons to stop “external” forces from interfering in Syria’s bloody civil war. The announcement sparked a panic in the intelligence services of the U.S. and its allies, which stepped up their efforts to block shipments of precursors for those weapons from entering the country.

“This is a more serious moment than July,” the official said.

CNN confirmed the report later on Monday. A U.S. intelligence official told the network that the U.S. obtained intelligence over the past weekend indicating this concerning development.

The intelligence, the official said, came from multiple sources but declined to provide any more specifics about how the U.S. learned the information.

The report came several hours after the Damascus government promised that it wouldn't use chemical weapons against its own people.

In a statement broadcast on government-run national television, the country's foreign ministry assured the international community that Assad would not approve such a measure.

"In response to the statements of the American Secretary of State, who warned Syria against using chemical weapons, Syria has stressed repeatedly that it will not use these types of weapons, if they were available, under any circumstances against its people,” the statement said.

The statement came following one by U.S. Secretary of State Hillary Clinton, who said earlier in the day, “This is a red line for the United States. I'm not going to telegraph in any specifics what we would do in the event of credible evidence that the Assad regime has resorted to using chemical weapons against their own people. But suffice to say we are certainly planning to take action.”

A similar “red line” on chemical weapons was drawn for Assad by U.S. President Barack Obama in a statement he made in August from the White House.

"We cannot have a situation where chemical or biological weapons are falling into the hands of the wrong people,” Obama told reporters at the time. “We have been very clear to the Assad regime – but also to other players on the ground – that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized.”

Israel has expressed concern that the chemical weapons arsenal maintained in Syria will indeed end up in the wrong hands – specifically, the hands of Hizbullah or other terrorists who aim to annihilate the Jewish State.

A report published Monday by The Atlantic indicated that Israel has consulted with Jordan twice over the issue of Syria's chemical weapons arsenal, both times with plans to take out multiple sites.