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With international support growing for action against embattled Syrian President Bashar al-Assad, questions mounted Tuesday over how the U.S. can confirm reports that the regime used chemical weapons against rebel strongholds.

In an interview with Jonathan Hunt on Foxnews.com LIVE, Georgia Institute of Technology Associate Professor Margaret Kosal talked about what factors U.S. officials are looking for to determine the use of these weapons.

“At this point it seems they are basing their assumption on the initial reports … they are looking at the symptoms,” said Kosal.  “What are people displaying ... one of the classic indicators of use of a nerve agent like sarin [gas] is what are called pinpoint sized pupils and those are seen on a number of the videos.”

As the White House draws closer to a decision on Syria, Kosal believes the evidence supports a chemical attack.

“From everything I’ve seen at this point I can’t say it’s undeniable,” said Kosal. However, she cautioned though that “the inconsistencies that have been observed point to the need for verification for real data before any political decisions are made.”

Watch the full interview with Margaret Kosal above and catch "On the Hunt" with Jonathan Hunt weekdays at 12 p.m. ET on FoxNews.com LIVE.