At the Friends of Syria meeting in London on Thursday, ministers from group's members Britain, Egypt, France, Germany, Italy, Jordan, Qatar, Saudi Arabia, Turkey, the United Arab Emirates and the United States vowed to funnel more aid to moderate Syrian rebels.
"We have to redouble our efforts, all of us, in support of the moderate opposition in order to bring about a peaceful resolution that the people of Syria want," said US Secretary of State John Kerry.
British Foreign Secretary William Hague said his country had promised an additional $50 million in "practical support" for the opposition.
The US and British initiatives coincided with an announcement by medical charity Medecins Sans Frontieres (MSF) that five of its staff had been freed in Syria after months of capivity.
The five were kidnapped by an armed group in January in northern Syria. MSF said three had been released on April 4 and the remaining two on Wednesday.
Boosting aid efforts
Hague said the Friends of Syria group was determined "to step up our efforts to deliver humanitarian aid across borders and across lines irrespective of the consent of the regime."
Kerry, whose country has provided around $1.7 billion in humanitarian aid, voiced his frustration over the difficulties in delivering food and medical aid to civilians in Syria.
More than 150,000 people have been killed in the country's three-year civil war and 3.5 million Syrians live in areas that aid convoys are unable to reach.
"It is not getting to people. It's going through one gate, one entryway, and it's going through Damascus and/or controlled by the Assad regime. That's unacceptable," said Kerry.
"We're going to join with other countries in an effort to try to guarantee accountability through the UN in making that happen," he added.
The group also hit out at President Bashar al-Assad's plan to seek another term in office in the restive country's June 3 election. Kerry said that Syria's upcoming vote was a "farce," an "insult" and a "fraud on democracy."
In a joint statement, the 11-nation group called on the international community to reject what would be "illegitimate" results from Assad intended election.
"In one unified voice, we are rejecting any notion whatsoever that the elections that the Assad regime has called somehow have any legitimacy whatsoever," said Kerry.
Kerry also said he had seen unverified "raw data" that suggested chlorine had been used as a chemical weapon by the Syrian government. He said there would be "consequences" if the claims turned out to be true.
As the ministers gathered for the meeting in London, at least 43 people were killed near a rebel-held border crossing between Syria and Turkey when a car bomb ripped through a crowded garage.
dr/ipj (AFP, dpa, AP, Reuters)