The US has not yet confirmed that toxic gases were employed in Syria, as Syrian activists have claimed, but Obama had previously warned that such actions would cross a "red line."
"Has that red line now been crossed?" BBC News asked on Thursday, referring to accusations that Assad's forces used chemical weapons to kill over 1,100 people in a poison gas attack earlier this week.
Syria is in the midst of a brutal war pitting Assad against an armed rebellion in violence believed to have killed over 100,000 people in the past several years.
This is not the first time chemical warfare has been reported in Syria, but Obama said the latest developments could prove "very troublesome" and "require America's attention," according to the Associated Press.
A top US official told The Wall Street Journal on the condition of anonymity on Wednesday that Washington is inclined to believe chemical weapons were indeed used recently in Syria.
"There are strong indications there was a chemical weapons attack—clearly by the government," the official said.
Obama told CNN that the Syrian government is not likely to be forthcoming on the issue, despite prodding by Russia, a close ally of Assad.
"We don't expect cooperation [from the Syrian government], given their past history," Obama told CNN's "New Day" anchor Chris Cuomo in an exclusive interview released on Friday.
But now, the US leader said "core national interests" are at play in the Syrian conflict, "both in terms of us making sure that weapons of mass destruction are not proliferating, as well as needing to protect our allies, our bases in the region," he said, according to CNN.
Obama also addressed recent developments in Egypt. Watch his interview here:
MOSA’AB ELSHAMY August 14, 2013
The US government gives Egypt $1.3 billion a year. Egypt then uses that money to buy weapons from US corporations.KYLE KIM August 16, 2013