WASHINGTON (AP) — Defense Secretary Leon Panetta says the U.S. has serious concerns that Syria is thinking of using its chemical weapons.

Panetta did not say what new intelligence information he has about the intentions of President Bashar Assad. But the defense secretary said it’s enough to raise U.S. fears that the use of chemical weapons ‘‘is being considered’’ by Syria.

Other U.S. officials said this week that intelligence agencies have detected that Assad’s government has been preparing its chemical weapons stockpiles for possible use.