The President and Prime Minister Harper spoke today by phone to discuss their grave concern about the Syrian regime's use of chemical weapons against civilians near Damascus on Wednesday, August 21. The United States and Canada agree that the international norm against the use of chemical weapons is longstanding and universal, and the use of chemical weapons anywhere diminishes the security of people everywhere. We continue to call for a strong international response to reinforce the prohibition on the use of chemical weapons to send a clear message that this kind of atrocity can never be repeated. The President and Prime Minister pledged to continue to consult closely on potential responses.
Barack Obama, Readout of the President's Call with Prime Minister Harper of Canada Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/304897