PARIS: US Secretary of State John Kerry continues a diplomatic offensive in Europe on Sunday to win backing for military strikes in Syria, after Washington and Paris said support for action was growing.
Heading into a crucial week for US plans to launch the strikes, Kerry was meeting with Arab League ministers in Paris and was set to head to London next before returning to Washington on Monday to continue rallying support at home.
The US Congress returns from its summer break on Monday to consider President Barack Obama's plans for strikes and UN inspectors are to release a report into an alleged chemical weapons attack by the weekend.
Fighting continued to rage inside Syria, with reports that rebel forces had taken control of the historic Christian town of Maalula, north of Damascus.
Washington accuses the Assad regime of gassing more than 1,400 people to death in an August 21 attack outside Damascus and wants to launch punitive strikes.
On Saturday, Kerry and French Foreign Minister Laurent Fabius insisted that international support for military action was increasing, after the EU issued a statement calling for "strong" action against Syrian President Bashar al-Assad's regime.
The EU statement did not call for military action but did condemn the "cynical use of chemical weapons."
Kerry said Saturday he was "encouraged" by the "very powerful statement" made by the 28-nation bloc.
More nations were getting behind the need for military action and the number of countries ready to take part was now in the "double digits", he said.
Obama, who is set to address the nation on Tuesday, is facing an uphill battle to convince a sceptical Congress -- and a war-weary US public -- of the need for action.
According to a Washington Post survey, 224 of the current 433 House members were either "no" or "leaning no" on military action as of Friday. A large number, 184, were undecided, with just 25 backing a strike.
On Saturday, a US congressional panel posted graphic videos of what senators were told were Syrian victims of the August attack, many of them children.
The 13 videos were shown to members of the Senate Intelligence Committee on Thursday, according to the panel's website.
US broadcaster CNN also aired the videos, with excerpts showing convulsing children and men sprawled on the floor vomiting and foaming at the mouth.
Meanwhile, the Los Angeles Times reported on Sunday that the Pentagon was preparing for three days of attacks on Syria, longer than originally planned.
War planners now aim to unleash a heavy barrage of missile strikes to be followed swiftly by additional attacks on targets that may have been missed or remain standing after the initial launch, the newspaper cited officials as saying.
-- 'Munich moment' -- Outlining his case in Paris on Saturday in French and English, Kerry compared the situation to the 1938 Munich Agreement, which ceded control of part of Czechoslovakia to Nazi Germany.
"This is our Munich moment, this is our chance to join together and pursue accountability over appeasement," he told reporters at a joint news conference Fabius.
"This is not the time to be silent spectators to slaughter."
He said Obama had made no decision about whether to wait for the release of a UN investigation into the August attack before taking action.
Fabius told reporters there was "wide and growing support" for action on Syria.
"Right now, seven of the eight countries in the G8 share our opinion on a strong reaction and 12 countries of the G20 also share this opinion," he said.
French President Francois Hollande, who has said Paris will wait for the results of the UN probe, said he expected the report to be ready by next weekend.
Hollande said he also expected a US Congress vote on "Thursday and Friday".
Inside Syria, rebel forces were in control of Maalula after fierce fighting overnight that saw regime troops withdraw to the outskirts of the town, residents and the Syrian Observatory for Human Rights watchdog said.
Maalula is a symbol of the Christian presence in Syria, and many of its inhabitants speak Aramaic, the language spoken by Jesus Christ that only small, scattered communities around the world still use.
After his meeting with Arab League officials in Paris, Kerry was to fly to London for talks with Palestinian president Mahmud Abbas on Sunday and meet British Foreign Secretary William Hague on Monday morning.
Hague on Sunday said although the British parliament had rejected military action against Syria, he backed US-led air strikes against the regime.
"I do believe very strongly that the world must stand up against the use of chemical weapons. The risks of not doing so in my view are greater than the risks of doing so," Hague told BBC television.
"This issue is about chemical weapons, which is a bigger issue than Syria."
On Saturday, Kerry met European foreign ministers in Vilnius, after which EU foreign policy chief Catherine Ashton read out a statement dubbing the suspected chemical attack "a war crime and a crime against humanity".
There was "strong evidence that the Syrian regime is responsible," the statement said.
The Syrian conflict, which began in March 2011, has left more than 100,000 dead, according to the United Nations.