US Secretary of State John Kerry met Sunday with Arab League foreign ministers in Paris to garner support for US-led military action in Syria, dpa reported.
The 22-member bloc, which in March gave Syria's seat to the opposition coalition, has not endorsed a strike by the West, stressing instead the need for a political solution to the 29-month conflict and engagement of the United Nations in any action on Syria.
From France, Kerry is set to travel to London, where he will meet with Palestinian President Mahmoud Abbas and British Foreign Secretary William Hague on Monday. The British parliament voted against military intervention in Syria last week.
Kerry met EU foreign ministers in Lithuania on Saturday, when the bloc called for a "clear and strong response" to the alleged use of chemical weapons in Syria, saying there was "strong evidence" that President Bashar al-Assad's regime was behind the August 21 attack.
The meetings come as the White House attempts to win over sceptics at home and abroad who are anxious about the possible unintended consequences of striking the al-Assad's regime.
President Barack Obama's administration is planning a media blitz ahead of an expected vote in the US Congress later this week on a resolution that would authorize a limited strike.
White House Chief of Staff Denis McDonough is set to appear on several Sunday morning political talk shows in the US.
On Monday, Obama is scheduled to give six television interviews on Syria before taking his case directly to the American public with an address to the nation Tuesday evening from the White House.
In a press conference with French Foreign Minister Laurent Fabius on Saturday, Kerry said the number of countries who now back US military action in Syria is in "double digits."
"This is really our Munich moment," Kerry said, referring to the 1938 agreement by European powers to allow Nazi Germany to occupy part of Czechoslovakia - an act now denounced as a policy of appeasement towards Adolf Hitler.
Fabius and French President Francois Hollande have argued for a military response to the toxic gas attack charges, which the US said killed 1,429 people, including 426 children, on August 21 outside Damascus.
But with a divided French public voicing doubts about the reliability of the evidence of such an attack, the government said it would wait for the results of a UN investigation before taking action.
Britain, Spain, Italy and Germany have also expressed support for a US response.
In Syria, Islamist rebels took control of the Christian town of Maalola north of Damascus, after clashes with the military and local militias, a pro-opposition watchdog group said Sunday.
The rebel fighters, mainly from the al-Qaeda-aligned al-Nusra Front, seized the town overnight, the Syrian Observatory for Human Rights said.
At least 17 rebels were killed and dozens of troops and militiamen were killed or injured, according to the organization that monitors the Syrian conflict from its base in Britain.
The opposition Syrian National Coalition said that forces from the rebel Free Syrian Army (FSA) would protect the town's residents and churches, a move aimed at dispelling worries that local Christians could be mistreated by Islamists.
"The Syrian regime is shamelessly seeking to intimidate Syrians and the world by giving the impression that the revolutionaries ... are like wild animals that want to devour minorities," said the coalition and FSA in a joint statement.
Thousands of Christians have left Syria since the uprising against the government of Bashar al-Assad began in March 2011, fearing persecution by the Islamists fighting to oust him.
The United Nations says more than 100,000 people have been killed since March 2011.
Last week, the UN said the Syrian conflict has displaced 6.25 million people - the world's largest refugee population. Some 2 million Syrians - more than half of them children - have fled the country, and 4.25 million are internally displaced.