Obama in the Press Room at the White House
President Barack Obama is spending his second day in New York City on Tuesday, where he will address the United Nations General Assembly, the White House said. Reuters

President Barack Obama today said that the use of chemical weapons in Syria would be a "red line" that would then spur the U.S. to action in Syria.

"There would be enormous consequences if we start seeing movement on the chemical weapons front, or the use of chemical weapons," the President said on Monday to White House reporters. "That would change my calculations significantly."

The U.S. has thus far restrained itself from jumping into the action in Syria, but Obama said Washington has been monitoring the situation "very carefully" and have "assembled a range of contingency plans," according to the AP.

Syria first acknowledged last month that it had chemical weapons, but Obama said he was "absolutely certain" that the stash was secure.