"A clear and strong response is crucial to make clear that such crimes are unacceptable and that there can be no impunity," EU foreign policy chief Catherine Ashton said after the meeting.
She said that information the EU has "seems to indicate strong evidence that the Syrian regime is responsible for this attack" of August 21 that killed hundreds of people in Syria.
As EU member states have different opinions on the need to take military action against the Syrian regime, the ministers voiced support for the French position to wait for conclusions of a UN probe before making any decisions on further actions.
EU minister also urged the UN Security Council to take responsibility and "unite in it's efforts to prevent any further chemical attack."
Having veto rights at the UN Security Council, Russia and China have so far refused to back a military intervention in Syria.
Asked at a press conference whether the EU decided that a mandate of the Security Council was not needed for military action, Ashton said that the EU supports the United Nations but recognizes "the realities".
"The European Union has always been a strong supporter of the United Nations and of the work of the Security Council. But we recognize also the realities of the situation at the present time," she said.
Ashton announced the EU position following EU ministers' meeting with US Secretary of State John Kerry, who wants international backing of US President Barack Obama's plans attack Syria.
Kerry, who came to Vilnius on Saturday to seek support for a military intervention in Syria, has welcomed EU foreign ministers' statement calling for a "clear and strong response" to a recent chemical attack in Syria.
"We are very grateful for the statement that came out of the meeting today with respect to Syria – a strong statement about the need for accountability," Kerry told a press conference in Vilnius.
The US secretary of state held a short press conference after meeting with EU foreign ministers who spent two days debating possible actions against Syrian President Bashar al Assad's regime.
Meanwhile Lithuanian Minister of Foreign Affairs Linas Linkevičius said he supported the US "active role" in the resolution of the Syrian crisis.
"We appreciate the US active role, we cannot stand by. There is growing evidence that Assad is responsible for all those crimes. We cannot ignore that, we must ensure that chemical weapons are not used in the future," Linkevičius told journalists.
