WASHINGTON
US President Barack Obama said that they had evidence pointing out to the use of chemical weapons in Syria but they did not know exactly how the chemical weapons were used, who used them, and when the chemical weapons were used.
President Obama's remarks came at a press conference held in Washington marking the 100th day of his second term.
President Obama stressed that the US had to be more certain of all the facts before a decision gets taken to intervene in Syria.
Obama stated that, if it was indeed determined that the Assad administration used chemical weapons, "we would have to rethink the range of options that are available to us".
Obama said the Syrian conflict was a "blemish on the international community generally".
President Obama underlined that the possible use of chemical weapons in Syria would mark the crossing of a "red line" and a game changer.
"I have got to know, I have got the facts (on Syria)," Obama noted.
"We do not know who used them. We don't have a chain of custody that establishes exactly what happened," Obama stressed.
Obama added that the international community had to be completely confident in the assessment that chemical weapons were used.
