BEIRUT: The United States government believes Syria has moved some of its chemical weapons in recent days, an official told CNN Friday.

The source told the U.S. new service that they believe the weapons are under the control of Syrian government forces.

The official added that the types of chemical weapons and reason behind the move are unclear.

However, the motive could range from wanting to protect the weapons from the fighting to wanting to use them against its own people.

Since the popular uprising began last March, the U. S. has been surveying Syria’s key weapons sites via satellite.

The Pentagon has refused to publicly comment on the matter, saying that Syria needs to ensure that its weapons stockpile is protected.

"We have repeatedly made it clear that the Syrian government has a responsibility to safeguard its stockpiles of chemical weapons, and that the international community will hold accountable any Syrian officials who fail to meet that obligation," said Victoria Nuland, the State Department spokeswoman.