The White House has downplayed media speculations that chemical weapons had been used by President Bashar al-Assad's regime against the Syrian rebels.
According to a recent report in the Foreign Policy magazine, a secret American investigation revealed that Assad forces used a poisonous gas against the rebels in Homs city Dec 23, 2012.
"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 programme," White House National Security Council spokesperson Tommy Vietor said in a statement.
The official reiterated, though, that Assad's government would be still held responsible for any potential chemical attack against the Syrian opposition forces or failure to ensure security of its stockpile of chemical weapons.
"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 CIA says Syria has had a chemical weapons program "for years and that the weapons can be delivered by aircraft, ballistic missile, and artillery rockets". But Syria has never deployed the weapons, although it warned last summer that they could be used against "foreign invaders".
At least 60,000 people have been killed in Syria's conflict since March 2011, UN High Commissioner for Human Rights Navi Pillay has said, citing new analysis released by the UN early January.