The European Union's foreign policy chief Catherine Ashton said on Saturday the EU's 28 nations agreed that available information seemed to show strong evidence that the Syrian government carried out a chemical attack on civilians in August.
"(The government) is the only one that possesses chemical weapons agents and the means of their delivery in a sufficient quantity," Ashton told reporters after meeting EU foreign ministers in the Lithuanian capital of Vilnius.
The ministers agreed, she said, that the world "cannot remain idle" and said a clear and strong response was needed to prevent any future use of chemical weapons in Syria.
But they stopped short of lending support to military action proposed by the United States and France. Washington says the August 21 attack killed more than 1,400 people.
Ashton said EU ministers welcomed French President Francois Hollande's commitment to wait for a report by United Nations inspectors on the incident before taking any action.
"The EU underscores...the need to move forward with addressing the Syrian crisis through the U.N. process," she said.