The European Union called Saturday for a “clear and strong” international response to what it said was “strong evidence” that Syrian President Bashar al-Assad’s government was responsible for a massive chemical weapons attack two weeks ago near Damascus, the country’s capital.

But the E.U. statement stopped far short of endorsing a U.S. military strike — something that U.S. officials acknowledged many of the organization’s 28 member states do not support.

E.U. foreign ministers, after listening to Secretary of State John F. Kerry explain the limited strike President Obama is considering, indicated that no action should take place at least until U.N. chemical weapons inspectors release a report on their Syria investigation, expected some time this month.

A similar delay was advocated Friday by French President François Hollande, whose government had said until last week that it was “ready” to participate in a U.S.-led military strike against Syria.

Kerry, speaking earlier Saturday with Lithuanian Foreign Minister Linas Linkevicius, whose government hosted the E.U. meeting in Vilnius, the Lithuanian capital, expressed gratitude for the bloc’s “support for efforts to hold the Assad regime accountable for what they have done.”

Later in the day, in Paris, Kerry spoke in French to deliver a lengthy and impassioned appeal to a deeply skeptical French public. Recalling U.S.-French partnership from the Revolutionary War through World War II, Kerry said: “This is our Munich moment . . . our chance to join together and pursue accountability over appeasement.”

The 1938 deal to which Kerry referred — reached by European powers with Adolf Hitler in an attempt to head off war — is usually associated more with Britain than France. Late last month, the British Parliament rejected a motion proposed by Prime Minister David Cameron to authorize participation in a U.S. strike against Syria.

Standing at Kerry’s side in a news conference, French Foreign Minister Laurent Fabius sought to fend off comparisons to the prelude to the Iraq war in 2003, when France was the United States’ strongest Western critic.

“The United States and France are side by side . . . every time the cause is just and is essential,” Fabius said, deriding “false comparisons to Iraq, which has absolutely nothing to do with this.”

“In Iraq, the weapons of mass destruction didn’t exist,” he said. “Here, the weapons of mass destruction exist.” Explaining Hollande’s change of heart, Fabius said his government understood public reluctance but suggested that the U.N. report would change minds.

As of Sept. 4, lawmakers appear to be tentatively dividing into four camps over military action in Syria.

Noting the E.U. statement and others, Kerry said, “We are building support.” He said that “there are a number of countries, in the double digits, who are prepared to take military action,” although he did not name them.

While U.N.-certified evidence of a chemical attack may make some Europeans more comfortable with the use of force, others say no military action should take place without U.N. authorization — a development that remains unlikely. China and Russia, Assad’s main military and political backer, have indicated that they will continue to veto U.N. Security Council resolutions against Assad.

“Those responsible should be brought to justice,” Linkevicius said in Vilnius. “We will make full use of the United Nations.” But neither he nor other E.U. members spelled out what action, short of a military strike and without a U.N. agreement, could be used to bring Assad to heel.

On Friday, U.N. Secretary General Ban Ki-moon called military action “ill-considered” and warned of “serious and tragic consequences.” He reiterated U.N. insistence that only the Security Council could authorize a military strike against a member state.

Any delay caused by waiting for the U.N. report appears increasingly insignificant, since the congressional approval President Obama is seeking may take even longer, if it is ever obtained.

The Senate might vote next week on a resolution authorizing the use of military force. In the House, where so far only a small minority has publicly voiced support for the measure, it remains the subject of sharp debate.

Kerry, who will meet here Sunday with representatives from the Arab League on both Syria and the Israeli-Palestinian peace process, is seeking foreign support during a weekend break from efforts to persuade Congress. He plans to travel to Britain on Sunday before returning Monday to Washington.

The E.U. statement includes some of the same language as a call by 10 members of the Group of 20 leading economic powers for a “strong international response” to the chemical attack. That statement, released by the White House on Friday, was crafted after members of the G-20 failed to agree on a joint position during a summit last week in Russia that was attended by Obama.

Germany, which had declined to sign the Friday statement, said Saturday that it would now do so, after what Foreign Minister Guido Westerwelle said was the “excellent and very wise position of the E.U.”

Michael Birnbaum contributed to this report.