U.S. Defense Secretary Chuck Hagel on Thursday said the U.S. intelligence community believes the Syrian government has used sarin gas on a small scale against rebels trying to overthrow the government of Bashar al-Assad.

"This morning the White House delivered a letter to several members of Congress on the topic of chemical weapons use in Syria. The letter ... states that the U.S. intelligence community assesses with some degree of varying confidence that the Syrian regime has used chemical weapons on a small scale in Syria,'' 

Hagel told reporters traveling with him. He said it was sarin gas.