"I do not know what the president will ask for from Congress in the days ahead or whether or not I will support his request," said Miller. "I will, of course, give his request the sober and thorough consideration that it deserves."
Miller added he would not support an "open-ended or unlimited" commitment in Syria.
"Like most Americans I am wary of getting America involved in yet another war," said Miller. "I will weigh this concern against the very serious concern I share with the president over the use of chemical weapons in violation of the Chemical Weapons Ban Treaty."