U.S. military action against Syria would carry the risk of inadvertently hitting a chemical weapons site, President Barack Obama told to PBS television in an interview on Monday.

“Have we mapped all of the chemical weapons facilities inside of Syria to make sure that we don’t drop a bomb on a chemical weapons facility that ends up then dispersing chemical weapons and killing civilians, which is exactly what we’re trying to prevent?” AFP news agency quoted Obama as saying during the interview.

Obama further expressed skepticism over whether setting a no-fly zone or waging a major military offensive against Damascus would save lives or change balance of power on the battlefield.

Supporters of a bold intervention in Syria failed to understand the complexity of the situation as there is no one simple solution, Obama said. “If you set up a no-fly zone, that you may not be actually solving the problem,” he added.

Obama’s show of skepticism over military action in Syria comes after his deputies announced plans to arm vetted Syrian rebels last week.

When asked to respond on calls to shut down Syria’s combat aircraft with American air power, Obama said “the fact of the matter is for example, 90 percent of the deaths that have taken place haven’t been because of air strikes by the Syrian air force.”

“The Syrian Air Force isn’t particularly good. They can’t aim very well,” he said, adding that most of the action was taking place “on the ground.”

He also said the possibility of creating “humanitarian corridor” to safeguard civilians in areas controlled by the opposition, would require bombing raids that could kill more civilians.

“Or if you set up a humanitarian corridor, are you in fact committed not only to stopping aircraft from going that corridor, but also missiles?

“And if so, does that mean that you then have to take out the armaments in Damascus and are you prepared then to bomb Damascus? And what happens if there’s civilian casualties?”

Syria chaos can’t continue

While explaining the complexity of military intervention in Syria, Obama said that “ongoing chaos” cannot continue in Syria.

“We can’t have the situation of ongoing chaos in a major country that borders a country like Jordan which in turn borders Israel,” he said, adding Washington has “serious interests there and not only humanitarian interests.”

Obama against sectarianism

The U.S. president in the interview said he opposed siding with the Sunnis in the Syrian conflict as some voices in the region have demanded, saying that would not serve American interests.

The two-year Syrian conflict that has killed at least 95,000 people is increasingly polarizing the region between its two major sects, Sunnis versus Shiites.

The Lebanese Shiite group, Hezbollah, played a key role in supporting Assad regime, which is mainly controlled by minority Allawites, a sect that is an offshoot from Shiite Islam. Meanwhile, Sunni clerics legitimized jihad against Assad regime last week especially after Hezbollah made it public that is in Syria and backing the Syrian troops against rebels.

Obama said the U.S. administration wanted to see a tolerant government in Syria that was “not sectarian.”