Outside powers need to act fast to protect Syrians because foreign military backing for the government is "changing the equation" of the war, Qatar's foreign minister said on Wednesday.
For 14 days, a Russian-backed Syrian government offensive has been underway to capture eastern Aleppo and crush the last urban stronghold of a revolt against Syrian President Bashar al-Assad that began in 2011.
HE the Foreign Minister Sheikh Mohamed bin Abdulrahman al-Thani  told a news conference in Singapore on Wednesday that the Friends of Syria group - an alliance of mainly Western and Gulf Arab countries who oppose Assad - had since February "stopped and minimized" its supply of weapons to rebels.
"On the other hand, the regime is continuing to receive supply from its allies, and that is what is changing the equation right now, and we hope that we can do something to protect them," the Foreign Minister said in answer to a question.
"We are very much concerned that the international community doesn't have a Plan B for the Syrian conflict and the bombing and the shelling of the Syrians will continue. We need to act very fast to protect the Syrian people."
The United States maintains that negotiations are the only way to end the violence in Syria.
US Secretary of State John Kerry, who announced on Monday that Washington was suspending talks with Moscow due to Russia's role in the offensive, has said peace efforts must carry on.