UN chief's warning of 'ill-considered' strikes further isolates Obama on Syria

The comments come after Obama made his case for retaliatory strikes during a four-hour dinner at the G-20 Thursday night. White House spokesman Ben Rhodes told reporters afterwards that the president is confident a “solid number” of countries will end up backing U.S.-led strikes.

Ban has repeatedly called for Assad to be held to account if the allegations are proven true, but only through U.N. action.

“I have repeatedly stressed that any use of chemical weapons by anyone under any circumstance would be a serious violation of international law and an outrageous crime,” he said Thursday at the G-20. “We cannot allow impunity in any crime against humanity.

“I believe that the topic of chemical weapons is critically important for international peace and security, and I take note of the ongoing debate over what course of action should be taken by the international community. All those actions should be taken within the framework of the UN Charter, as a matter of principle.”

The Obama administration argues that the United States is justified in acting, even alone, because the U.N. is hopelessly stuck. 

“On occasion, as we had with Kosovo ... we cannot allow the patron of a party to the conflict, the patron of the actor that itself violated this international norm, to act with impunity simply because it has that patronage on the Security Council,” U.S. Ambassador to the U.N. Samantha PowerSamantha Jane Power8 signs pointing to a counterintelligence operation deployed against Trump's campaign 115 former US ambassadors write Senate opposing Gina Haspel Trump expected to remove US from Iran nuke deal MORE said Thursday. “That in no way reflects the spirit of the UN charter or the intentions of the founders or the intentions of any of us who come to work every day with the hope of promoting and enforcing international peace and security.

“In this case, with regard to this mass casualty chemical weapons use and the risk of further use, the risk, as the Secretary General said, of this becoming a weapon of war, to stand back would be to endanger not only international peace and security, not only U.S. national security, but we also believe the very international system that we have been working these decades to build.”

Please send tips and comments to Julian Pecquet: jpecquet@thehill.com

Follow us on Twitter: @TheHillGlobal and @JPecquetTheHill