Obama and other administration officials were preparing a days-long push to gain public and congressional support for a strike on Syria. The challenges they faced were apparent Saturday. Sen. Mark Pryor, an Arkansas Democrat, said he would oppose military action, and dozens of people picketed outside the White House against Obama's request.
Pryor said in a statement that the administration had not met his criteria for gaining his support: a compelling national security interest, a clearly defined mission with a definitive end, and a coalition of allies.
"Unless there's some new information or some new development or circumstance, I just don't see me changing my vote at this point," he told The Associated Press in an interview.
Protesters at the White House chanted "They say more war; we say no war" and said their picket line marked a line Congress should not cross as it prepared to vote on the issue.
In Britain, an anti-regime monitor of the fighting in Syria says it has been compiling a list of the names of the dead from the Aug. 21 attack and that its toll has reached 502. The Obama administration reported 1,429 people died, including 426 children, citing intelligence reports. The Assad government blames opposition forces for the deaths.
"Punishment is not at odds with a political solution," Fabius said. "Bashar Assad will not participate in any negotiation as long as he believes himself to be invincible."
Saturday's developments left both the U.S. and Europeans in a waiting game.
While the Europeans awaited the U.N. inspection report, the Obama administration waited to see if Congress would back a use of force. Meantime, administration officials continued to lobby lawmakers by phone to vote to authorize a limited military strike against the Assad regime.
The first Senate vote, expected Wednesday, was likely to be on a resolution authorizing the "limited and specified use" of U.S. armed forces against Syria for no more than 90 days and barring American ground troops from combat. A final vote in the 100-member chamber was expected at week's end.
A House vote is likely the week of Sept. 16.
Asked about the American public's uneasiness about getting involved in another conflict, Kerry reiterated his view that the use of chemical weapons in the Syrian conflict was a threat to the U.S.
"This case has not yet been made to the American people for more than a few days and we will continue to make the case to the American people," Kerry said in Paris. "This concerns ever American's security."
The DVD compilation of videos of victims of the gas attack near Damascus was shown to senators during a classified briefing Thursday, and some of the videos were first broadcast Saturday on CNN. Supporters of the Syrian rebels had posted the videos on YouTube.
Senate Intelligence Committee Chairman Dianne Feinstein of California requested the material from the CIA, and members of her committee watched the videos Thursday. The DVD is a compilation of footage of victims of the Aug. 21 chemical weapons attack in the suburbs of the Syrian capital of Damasacus that were posted on YouTube by supporters of the Syrian rebels.
The U.S. official, who was granted anonymity to discuss the subject of a classified briefing, said the videos were also referenced in the government's four-page intelligence assessment, released last week, that blamed the Syrian government for the chemical attack.
Associated Press writers Raf Casert in Vilnius, Lithuania, Sarah DiLorenzo in Paris, Darlene Superville in Washington and Andrew DeMillo in Little Rock, Ark., contributed to this report.