The UN General Assembly has voted by a big majority to condemn its own Security Council for failing to end the unrest in Syria as fighting rages.
It passed a non-binding resolution, which also condemns the Syrian government's use of heavy weapons, by 133 votes to 12 with 31 abstentions.
The move came after the resignation of UN-Arab League envoy Kofi Annan and the failure of his six-point peace plan.
Government forces backed by tanks have launched a new assault in Damascus.
Shelling also continued on Friday in Syria's largest city, Aleppo.
Activists say more than 20,000 people - mostly civilians - have died in 17 months of unrest.
The General Assembly resolution expresses "grave concern" at the escalation of violence in Syria and deplores "the failure of the Security Council to agree on measures to ensure the compliance of Syrian authorities with its decisions".
"The first step in the cessation of violence has to be made by the Syrian authorities," the resolution said.
Saudi Arabia, the driving force behind the resolution, had urged the Assembly to maintain its moral and humanitarian values by approving the motion.
Syria's envoy, Bashar Jaafari, reacted to the vote by saying his government still supported Mr Annan's six-point plan.
Accusing Saudi Arabia and Qatar of having undermined the plan before coming out in support of it, he said: "You cannot be a fireman and an arsonist at the same time."
UN Secretary General Ban Ki-moon said the conflict in Syria had become a "proxy war" and called on powers to overcome their rivalries in an effort to end the violence.
"The acts of brutality that are being reported may constitute crimes against humanity or war crimes," he said.
Russia and China have blocked three attempts in the UN Security Council to impose sanctions against Damascus.
In Moscow on Friday, a delegation of Syrian ministers held talks on exporting crude oil to Russia in exchange for refined oil products, and also asked for a hard currency loan for their country. There was no immediate comment from Russian officials.
Meanwhile, fighting raged in the Tadamon district of Damascus for a second day.
Eyewitnesses and activists say government forces used dozens of tanks and armoured vehicles to attack what is seen as the rebels' last stronghold in the capital.
At least 15 people were reported killed when mortars hit the nearby Palestinian refugee camp at Yarmouk late on Thursday.
Hamas, the Palestinian group in power in the Gaza Strip, described the attack as a heinous crime - the Syrian government and rebels blamed one another.
Fighting has also continued in Aleppo, where government forces have been trying to reclaim areas seized by the Free Syrian Army (FSA) in the past two weeks.
UN peacekeeping chief Herve Ladsous told the Security Council that UN observers in Aleppo were seeing "a considerable build-up of military means, where we have reason to believe that the main battle is about to start".
One FSA fighter, Thoebah Knafane, told BBC News that winning Aleppo would "open the whole northern part of Syria" for the opposition.
Fighters, she said, were being trained in both Syria and Turkey and she personally had been instructed in using an M16 assault rifle and a pistol.
The FSA has issued a statement denying responsibility for the public killing of alleged government loyalists in Aleppo on Tuesday and condemning the shootings, video of which was posted online.
Separately, Russia's defence ministry has denied that a group of naval landing ships it is sending to the Mediterranean on exercises plans to call at its base in the Syrian port of Tartus.
In another development, Alistair Burt, UK Foreign Office minister for the Middle East, confirmed to the BBC that the UK would be providing further communications equipment to the opposition in Syria in the next month.
US media say US President Barack Obama has signed a covert order authorising support for Syrian rebels.