White House: Japan agrees 'there needs to be a response' on Syria

Earlier in the day, Rhodes said that President Obama would look to rally support from world leaders on a strike in Syria.

"The president will … have a chance to speak with allies of the United States and key partners to explain our current thinking on Syria," Rhodes said. "And I think we'll continue to work with those countries to see what type of political and diplomatic support they may express for our efforts to hold the Syrian regime accountable."

Even if the White House is unable to secure commitments for military aid, Obama is looking to build the case that the use of chemical weapons violates international standards.

"The president will talk to allies and partners about their ability to express support for the notion that an international norm that the international community has spent many, many years reinforcing must be upheld in Syria," Rhodes said. "And I think we've found common views on that position among some of our key allies and we'll continue to discuss that with them here."