DAMASCUS, Syria -- President Bashar Assad vowed Thursday that "Syria will defend itself" against western military strikes over a suspected chemical weapons attack, and the UN said inspectors will leave within 48 hours carrying information that could be crucial to what happens next.
British Prime Minister David Cameron argued strongly for military intervention in Syria but was rejected in a preliminary vote in Parliament, while French defence officials said openly for the first time their military is preparing for a possible operation. The administration of U.S. President Barack Obama was briefing congressional leaders about its case for attacking Syria.
The U.S., Britain and France blame Assad's regime for the alleged chemical weapons attack Aug. 21 on rebel-held suburbs of Damascus. The Syrian government denies the allegations, saying rebels staged the attack to frame the regime.
At the United Nations, a meeting of the permanent members of the Security Council on the Syrian crisis ended after less than an hour after being convened by Russia, a staunch ally of the Assad regime.
As western leaders made their case at home for intervening in Syria's three-year-old civil war, Assad remained defiant.
'They can construct from that evidence a fact-based narrative that can get at the key facts of what happened on the 21 of August'
"Threats to launch a direct aggression against Syria will make it more adherent to its well-established principles and sovereign decisions stemming from the will of its people, and Syria will defend itself against any aggression," he said in comments reported by the Syrian state news agency.
It's not clear whether Assad would retaliate against any attacks or try to ride them out in hopes of minimizing the threat to his continued rule. The U.S. has said regime change is not the objective of any military action it may carry out.
The UN experts have been carrying out on-site investigations this week to determine whether chemical weapons were used in the attack the group Doctors Without Borders says killed 355 people. Inspectors visited the eastern suburb of Zamalka, where they interviewed survivors and collected samples. Amateur video posted online showed UN inspectors in gas masks walking through the rubble of a damaged building. One inspector scooped pulverized debris from the ground, placed it in a glass container and wrapped the container in a plastic bag.
UN Secretary General Ban Ki-moon urged western powers to delay any military action until the experts can present their findings to UN member states and the Security Council. Speaking in Vienna, Ban said the UN team is to leave Syria on Saturday morning and will immediately report to him. He also said he spoke to Obama about ways to expedite the UN probe.
Some of the experts will take samples to laboratories in Europe after leaving Damascus, according to UN spokesman Farhan Haq, adding the team's final report will depend on the lab results and could take "more than days."
The mandate of the UN team is to determine whether chemical agents were used in the attack, not who was responsible. But Haq suggested evidence collected by investigators, including biological samples and interviews, might indicate who was behind the attack.
"Their mission is to determine whether chemical weapons were used. It's not about attribution. At the same time, I would like to point out that they will have a large number of facts at their disposal -- they have collected a considerable amount of evidence through samples, evidence through witness interviews -- and they can construct from that evidence a fact-based narrative that can get at the key facts of what happened on the 21 of August," Haq said.
British and American leaders, who have put the blame for the attack squarely on the regime's shoulders, faced pushback against possible punitive military strikes, particularly before the investigators release their conclusions.
In a stunning defeat Thursday night, Cameron's government lost a preliminary vote calling for military strikes. Although non-binding, the rejection means Cameron's hands are tied and he released a terse statement to Parliament saying it was clear to him the British people did not want to see military action.
Cameron had told British lawmakers it is legal and just to launch a military strike against Syria even without authorization from the UN Security Council. He argued Syria could repeat its alleged use of poison gas if the international community fails to act.
But he also said there is still a sliver of uncertainty over who was behind the alleged chemical attack and Britain would not act if it faced major opposition at the UN's top security body. "I think it would be unthinkable to proceed if there is overwhelming opposition in the Security Council," he said.
Obama also was trying to shore up political support for a move against Syria. The administration planned briefings for leaders of the House of Representatives and Senate and national security committees, U.S. officials and congressional aides said.
Obama, although still reportedly weighing his options, signalled Wednesday the U.S. was moving toward a punitive strike, saying he has "concluded" Assad's regime is behind the attacks and there "needs to be international consequences."
U.S. intelligence officials said the intelligence linking Assad or his inner circle to the Aug. 21 attack is no sure thing, with questions remaining about who controls some of Syria's chemical weapons stores and doubts about whether Assad ordered the strike.
Syrian officials have urged the UN inspectors to extend their mission to investigate what the regime alleges are three chemical attacks against Syrian soldiers this month in the Damascus suburbs.
Haq, the UN spokesman, said the UN team will leave despite the government's request, although the appeal is being given serious consideration and the experts intend to return to Syria to investigate other incidents.
French defence officials said publicly for the first time their military is preparing for a possible operation in Syria, but President Francois Hollande stopped short of announcing armed intervention.
Unlike Obama and Cameron, he has a freer hand to decide how to deal with the crisis -- Hollande does not need parliamentary approval to launch military action that lasts less than four months.
French Defence Minister Jean-Yves Le Drian said "the armed forces have been put in position to respond" if Hollande commits French forces to an international intervention.
France has a dozen cruise missile-capable fighter aircraft at bases in the United Arab Emirates and the Horn of Africa nation of Djibouti.
-- The Associated Press