BRUSSELS European leaders promised to send food and medicine to people trapped in the devastated city of Aleppo, with France's president calling for a U.N. resolution to support the EU response that Russia could not refuse.
EU aid trucks have been waiting to go into the rebel strongholds of eastern Aleppo since early October and are Europe's only tangible assistance in a conflict that has left it marginalized, unable to agree sanctions to pressure Moscow.
At an EU summit where German Chancellor Angela Merkel said the conflict was "shameful" and regretted the failure of EU diplomacy, French President Francois Hollande said Paris was working on a United Nations Security Council resolution to secure humanitarian aid corridors.
"Russia has used its veto many times on resolutions. But here, could Russia veto a resolution whose goal would be humanitarian? What responsibility would it take if it went so far?," Hollande said at a news conference.
Hollande said he hoped the resolution, on which diplomats would start work on Friday, would serve as a basis for a lasting ceasefire and the start of broader peace talks.
The summit chairman, Donald Tusk, said the bloc would use all diplomatic channels to press for humanitarian aid to reach Aleppo and the 50,000 people still trapped there.
Tusk said EU demands were the immediate opening of humanitarian corridors to allow aid into Aleppo, and for civilians to be evacuated safely under what he called "neutral, international supervision."
"There must be full and unrestricted access for all medical personnel and aid workers," Tusk said.
With no military role in the Syrian conflict, where Russia and Iran have played a decisive role in support of President Bashar al-Assad, EU leaders were eager to show action after a local Aleppo official made a personal plea at the summit in Brussels, saying it was time to go beyond statements.
"We are not waiting for press communiques and declarations, or meetings for the organisation of other meetings," said Brita Hagi Hassan, head of the city council for the part of Aleppo once under rebel control. "We want action," said Hassan, who has been outside of east Aleppo since the Russian-backed siege of rebel bastions this year.
Leaders did agree a joint statement condemning the violence and calling for a ceasefire but said it was a sign of their resolve to do more.
"We said that those that are responsible for breaches of international law must be brought to justice," Merkel said of the discussion among EU leaders.
Hollande also vowed to make Russia contribute financially to humanitarian aid and to help the wounded, particularly he said, after Russian warplanes had destroyed so many hospitals.
The EU - the world's largest aid donor - has said it will not pay for reconstruction Syria if Damascus and its allies wipe out any opposition and install a false peace there.
However, there was no breakthrough on British and French efforts to impose EU sanctions on senior Russian officials despite support from Poland.
They have been blocked by the Kremlin's allies in the bloc Hungary, Greece and Cyprus, and also complicated by Italy's strong business ties with Russia.
(Additional reporting by Gabriela Baczynska and Noah Barkin; Editing by Noah Barkin)