Obama gravely concerned by reports of CW usage in Syria

US President Barack Obama has said the alleged use of chemical weapons by Syrian forces that killed over 1,300 people is a "big event of grave concern" but cautioned against a costly American intervention that could "breed more resentment" in the volatile region.

"Well, we are right now gathering information about this particular event, but I can say that unlike some of the evidence that we were trying to get earlier that led to a UN investigator going into Syria, what we've seen indicates that this is clearly a big event of grave concern," Obama said.

Obama said his administration was already in communications with the entire international community following reports that Syrian President Bashar al-Assad's government used chemical weapons in an attack near Damascus on Wednesday that was said to have killed more than 1,300 people.

"We're moving through the UN to try to prompt better action from them. And we've called on the Syrian government to allow an investigation of the site, because UN inspectors are on the ground right now," Obama told CNN in an interview.

Last year Obama had said the use of chemical weapons in Syria would cross a "red line" and force a tough US response.

The US President however said he was not very optimistic whether Syrian regime would respond positively.

"We don't expect cooperation, given their past history, and, you know, what I do believe is that -- although the situation in Syria is very difficult and the notion that the US can somehow solve what is a sectarian, complex problem inside of Syria sometimes is overstated...," he said.

The Syrian government has described the allegations that it sanctioned the use of chemical weapons as "illogical and fabricated".

The international community, including Russia, have urged Assad to cooperate with a UN inspection team to pursue earlier allegations of chemical weapons attacks and to give them access to affected areas.

Obama is against US military action to protect civilians in Syria, fearing being drawn into a deadly civil war, just soon after he withdrew US troops from Iraq.

Obama also said Americans expect him to protect the country's long term interests.

He said, "sometimes what we've seen is that folks will call for immediate action, jumping into stuff, that does not turn out well, gets us mired in very difficult situations, can result in us being drawn into very expensive, difficult, costly interventions that actually breed more resentment in the region."

He said that "core national interests" of the US were involved 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."

"So, you know, I think it is fair to say that, as difficult as the problem is, this is something that is going to require America's attention and hopefully the entire international community's attention," Obama added.