The US Secretary of State, John Kerry, has said that many countries are prepared to take part in US-led military strikes against the Syrian regime for an alleged chemical attack in Damascus suburbs last month.
"There are a number of countries, in the double digits, who are prepared to take military action," Kerry said at a press conference on Saturday with his French counterpart Laurent Fabius.
"We have more countries prepared to take military action than we actually could use in the kind of military action being contemplated."
Kerry also said he was encouraged by a European Union statement calling for a "strong" response to the alleged Syrian chemical attack.
Heading into a crucial week for US plans to launch the strikes, Kerry was meeting Arab League ministers in Paris on Sunday and was set to head to London next before returning to Washington on Monday to continue rallying support at home.
Outlining his case in Paris 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 said.
"This is not the time to be silent spectators to slaughter."
In Riyadh, the Gulf Cooperation Council urged the international community to intervene immediately to "rescue" the Syrian people from "oppression".
Turning a blind eye
A carefully worded message from foreign ministers of 28 EU governments on Saturday stopped short of endorsing possible US and French military action against Syria ahead of the report by UN weapons inspectors, which France's president said could come by the end of the week.
In-depth coverage of escalating violence across Syria
Meanwhile, President Barack Obama urged Americans on Saturday to back him in launching an attack on Syria, as diplomatic pressure grew on the US to wait for the UN report.
Fresh from a European trip in which he failed to forge a consensus among G20 leaders, Obama plunged into a campaign on radio and television to try to convince a sceptical US public and Congress of the need for a military strike.
In his weekly address, Obama warned of the dangers of turning "a blind eye" to chemical attacks.
"I call on members of Congress, from both parties, to come together and stand up for the kind of world we want to live in," Obama said.
Obama has emphasised he favoured limited strikes on Syria to deter future chemical weapons attacks - not another costly and protracted conflict.
"This would not be another Iraq or Afghanistan," Obama declared in his weekly radio address, previewing arguments he will make in a nationally televised address on Tuesday.
The Obama administration says more 1,400 people were killed by the poison gas, hundreds of them children. But the Syrian government has denied it used chemical weapons on its people.
Vladimir Putin, the Russian president, has backed the Syrian President Bashar al-Assad and has insisted that UN should be involved in resolution of the conflict.
Russia, backed by China, has used veto power three times to block UN resolutions condemning Assad’s government.
Earlier on Saturday Catherine Ashton, the EU's foreign policy chief, said that "a clear and strong response" must be delivered to Syrian regime, but urged those advocating military strikes to wait for a UN inspectors' report.
Speaking in the Lithuanian capital, Vilnius, on Saturday, Ashton said that the EU agreed that available information showed strong evidence that the Syrian government was responsible for the alleged chemical weapons attack on civilians on August 21.
Ashton said the August 21 attack was a "blatant violation of international law, a war crime and a crime against humanity" and that the ministers "were unanimous in condemning in the strongest terms this horrific attack".
Obama has asked the US Congress to approve the use of force in Syria, and on Saturday announced that he will be doing a series of television interviews ahead of a nationwide televised address on Tuesday.
A final vote in the US Senate is expected at the end of the coming week. A US House of Representatives vote is likely the week of September 16.