AUBURN, N.Y. (CBS) - President Obama has called a possible chemical weapons attack in Syria a "big event of grave concern."
Mr. Obama said in an interview with CNN aired on Friday that the U.S. is still seeking confirmation that toxic gases were used in Syria. But he said the allegations were "very troublesome" and were going to "require America's attention."
However, the president said the idea that the U.S. can solve Syria's civil war is "overstated."
The U.S. has previously confirmed chemical weapons use in Syria, a step Mr. Obama said would cross a "red line." However, the American response has been minimal.
President Obama has come under mounting pressure from political friends and foes in Washington, and around the world, to take more significant action to stem the violence in Syria. His administration said weeks ago that it was prepared to start providing material assistance to rebel groups, but those supplies -- which include, theoretically, weapons -- have yet to arrive.
While the president has not publicly ruled out direct U.S. military intervention, Mr. Obama's chairman of the Joint Chiefs of Staff told a Democratic politician in a letter earlier this month that Syria's opposition effectively wasn't cohesive and trustworthy enough to consider an ally.
Without a reliable military partner already on the ground in Syria, the White House is reluctant to take any further measures without a solid international alliance behind it.
"If the U.S. goes in and attacks another country without a U.N. mandate and without clear evidence that can be presented, then there are questions in terms of whether international law supports it, do we have the coalition to make it work, and, you know, those are considerations that we have to take into account," Mr. Obama told CNN.
CBS News correspondent Margaret Brennan reported Friday on "CBS This Morning" that an increasing chorus of European nations are pinning the blame for this week's alleged chemical attack in the eastern Damascus suburbs squarely on the Assad regime, and urging decisive action, but the White House is keeping up the push for an international mandate.
French Foreign Minister Laurent Fabius said on Thursday that world powers must respond with force if allegations that Syria's government was responsible for the attack prove true. Fabius stressed, however, there was no question of sending in troops.
Russia called Friday on both the Assad regime and the rebels -- who control much of the eastern Ghouta suburbs of Damascus where the alleged chemical attack occurred -- to allow a team of United Nations inspectors already in the capital city access to the site, to try and verify the claims.
Opposition activists claim they have actually tried to smuggle human hair, tissue and mucus samples from victims of the attack to the inspectors at their hotel in Damascus, but have been unable to do so. Those claims could not be confirmed, and it was unclear whether the team of 20 scientists would even accept samples obtained under such circumstances for evaluation.
China, which, along with Russia, has blocked a tougher stance on the Assad regime as a permanent member of the UN Security Council, gave a more muted reaction Friday, saying the inspectors' conclusions should not be undermined by premature accusations of blame in the alleged chemical attack.
The Swedish Foreign Minister became the latest European diplomat Friday to suggest the attack in Ghouta -- if verified -- could only have been the work of Assad's forces, due to its scale.