US President Barack Obama this week warned that any use of chemical weapons in Syria would be a "game changer," but he would not take lightly any decision to intervene militarily in the Syrian conflict, analysts said.

After accusations by both sides that chemical weapons were used in an attack near the northern Syrian city of Aleppo Tuesday, UN Secretary General Ban Ki-moon announced Thursday he would launch a probe into the matter.

Obama said Wednesday the use of chemical weapons would amount to a "serious and tragic mistake," which some analysts interpreted as a hint that the United States could get directly involved in the deadly conflict.

But the president is unlikely to dive headlong into war-ravaged Syria, and will not take hastily any decision on military intervention, analysts said.

"Unless there is solid proof of Syrian government chemical weapon use this time or on another occasion, Obama almost certainly will avoid the complex, resource-intense option of military intervention," said Wayne White, former deputy director of the State Department's Middle East Intelligence Office.

Michael O'Hanlon, a senior fellow at the Brookings Institution, said it was "moderately likely" that the United States would get involved militarily on some level, as Obama's recent "game changer" remarks were consistent with previous comments.

"When he says that, it makes it harder not to do something," O'Hanlon said, adding that the most basic level of involvement might involve providing arms to the opposition, although such aid would start the United States down a path that could lead to further involvement.

"The problem is when you start to do a little more, if your first step doesn't make a meaningful difference in the conflict, then there's pressure to do even more," O'Hanlon said. "Once you're engaged in the conflict in a significant way, it's hard to see your side lose. And that means you feel pressure to do more if you need to later on."

While a full-scale US invasion will not happen, an air campaign is politically feasible, despite the US public's reluctance to involve the US troops in any further foreign military adventures following a decade-long war in Afghanistan and the widely unpopular war in Iraq.

It would be harder to imagine a stabilization mission, although even that is possible if it involves a multinational effort, if US troops provide the minority of the total force strength and if the risks to US troops seem relatively modest, O'Hanlon said.

"I don't want to rule out the possibility of a post-conflict stabilization force - like the one in Bosnia around 15 years ago - but that begins a very difficult political load for the president to lift. He would really have to marshal his political skills to do it," he said.

He added that any US involvement would not occur overnight.

White said the most likely option would be air strikes against a Syrian chemical weapons target, although Washington may not aim to cripple Syria's entire chemical weapons capability and may limit its operations to one major strike meant to send a warning.

The United States would likely seek the involvement of key NATO allies such as Britain, France, Italy, and perhaps Germany, although Berlin refused to participate in the Libyan operation and might decline again, White said.

However, if the situation were more urgent, and the United States had assets properly positioned in advance, Washington might feel the need to act more quickly and unilaterally, White said.

He noted that the United States, along with Israel and Britain, have had robust intelligence assets focused on Syria's chemical weapons arsenal, testing and training for more than 25 years. The United States, using satellite and other technical intelligence, and Israel, using satellite, other technical intelligence, drones, and Mt. Hermon visual observation, are especially capable, he said.

So any significant change in the status of those well-monitored sites and related movements, not merely chemical weapons use itself, could raise red flags and provoke a military response, White said.

Still, he noted the difficulty of US intervention in the face of Syria's formidable anti-aircraft defense, which has been a significant deterrent to setting up a no-fly zone or other aerial intervention by the United States and NATO.