Unnamed U.S. officials tell NBC News that the Syrian military has loaded the precursor chemicals for sarin nerve gas into aerial bombs.
The report comes hours after French weekly magazine Le Point reported that NATO special forces are preparing to enter Syria to secure its chemical weapons stockpiles.
On Monday, Secretary of State Hillary Clinton said that the U.S. is "certainly planning to take action" if new evidence showed that Bashar al-Assad's regime intended to use its stash of chemical weapons internally or cross-border.
Sarin gas, a colorless and odorless gas that can spread quickly through the air, is one of the most dangerous and toxic chemicals known to man. The Assad government has more than 500 metric tons of the precursors and usually stores them separately to prevent accidentally triggering a deadly reaction.
On Monday there were reports that the regime had reached the point "where they can load it up on a plane and drop it," but on Tuesday the Pentagon told NBC that there was no clear evidence that preparations had begun.
The Voice of Russia reports that there are now 17 warships off the Syrian coast following the arrival of the U.S.S. Dwight D Eisenhower — a multipurpose nuclear attack carrier that holds 70 fighter-bombers and 8,000 U.S. servicemembers — in the eastern Mediterranean.
In mid-November the U.S. ordered three warships on reserve to the coast of Israel. Senior U.S. military officers subsequently told CNN that the U.S. was considering further increasing the American military presence in the eastern Mediterranean. Russia responded by sending warships of their own off the coast of Gaza.