The White House on Tuesday appeared skeptical of reports from U.S. diplomatic officials in Turkey that the Bashar Assad regime had likely used some form of chemical weapon last month in the Syrian civil war, Reuters reported.
"The reporting we have seen from media sources regarding alleged chemical weapons incidents in Syria has not been consistent with what we believe to be true about the Syrian chemical weapons program," National Security Council spokesman Tommy Vietor said in released remarks.
"If the Assad regime makes the tragic mistake of using chemical weapons, or fails to meet its obligation to secure them, the regime will be held accountable," Vietor said.
The NSC spokesman was addressing a Tuesday report by Foreign Policy, which cited a classified State Department cable from U.S. diplomats in Istanbul who probed accusations by Syrian physicians, defectors, and regime opponents that Assad's military employed toxic gas on the city of Homs in a Dec. 23 attack.
"The main symptom of the respiratory ailments was bronchial secretions. This particular symptom was the cause of the death of all of the people," Homs-based neurologist Nashwan Abu Abdo said of the victims. "All of them died choking on their own secretions."
"They all had miosis -- pinpoint pupils. They also had generalized muscle pain. There were also bad symptoms as far as their central nervous system. There were generalized seizures and some patients had partial seizures. This actually is proof that the poison was able to pass the blood-brain barrier," Abdo added. "In addition, there was acute mental confusion presented by hallucinations, delusions, personality changes, and behavioral changes."
Officials questioned senior defector Mustafa al-Sheikh, a one-time Syrian army major general involved in the regime's weapons of mass destruction program..
The findings, inked by the U.S. consul general in Istanbul, Scott Frederic Kilner, were transmitted to Foggy Bottom last week, Foreign Policy said, citing an interview with an anonymous Obama administration official.
Top U.S. officials, including President Obama, have repeatedly threatened a harsh response against Damascus if it uses its chemical weapons. They have not said exactly what response should be anticipated.
The reported symptoms correspond with Agent 15, according to issue experts. Agent 15 is an incapacitating material covered under Schedule 2 of the Chemical Weapons Convention, according to Foreign Policy. A Schedule 2 material is deemed to pose "a significant risk to the object and purpose of this convention because it possesses such lethal or incapacitating toxicity as well as other properties that could enable it to be used as a chemical weapon."
Syria has not joined the international accord that prohibits the development, production, stockpiling or use of chemical warfare materials.
The U.S. State Department at a Wednesday press briefing said it "found no credible evidence to corroborate or to confirm that chemical weapons were used" in Homs, Foreign Policy further reported.
"It is a responsibility of our embassies and consulates around the world, no matter what kind of anecdotal information you have, to report it. That doesn't necessarily mean that either at the time or over the longer term it is considered credible by us," according to department spokeswoman Victoria Nuland.