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President Obama today said his administration has concluded that the regime of Bashar al-Assad is responsible for the recent chemical attack against Syrian civilians and that there "need to be international consequences," as he outlined the case for a "limited" U.S. response.

In an interview with PBS' NewsHour, the president said he has not made a decision about how to respond, but that he has "no interest in any kind of open-ended conflict" in Syria. "But we do have to make sure that when countries break international norms on weapons like chemical weapons that could threaten us, that they are held accountable," he said, in his most extensive comments since the Aug. 21 attack.

"If, in fact, we can take limited, tailored approaches, not getting drawn into a long conflict, not a repetition of, you know, Iraq, which I know a lot of people are worried about - but if we are saying in a clear and decisive but very limited way, we send a shot across the bow saying, 'Stop doing this,' that can have a positive impact on our national security over the long term … and may have a positive impact in the sense that chemical weapons are not used again on innocent civilians," he said.

As lawmakers increasingly call for the president to seek congressional approval for any military action, Obama argued the U.S. must protect its core self-interests.

"We want the Assad regime to understand that by using chemical weapons on a large scale against your own people, against women, against infants, against children that you are not only breaking international norms and standards of decency, but you're also creating a situation where U.S. national interests are affected and that needs to stop," he said.

The president warned about the broader repercussions of the use of chemical weapons in Syria.

"When you start talking about chemical weapons in a country that has the largest stockpile of chemical weapons in the world, where over time their control over chemical weapons may erode, where they're allied to known terrorist organizations that in the past have targeted the United States, then there is a prospect, a possibility in which chemical weapons that can have devastating effects could be directed at us. We want to make sure that that does not happen," he said.