The UN General Assembly is preparing to denounce Syria for unleashing tanks, artillery, helicopters and warplanes on the people of Aleppo and Damascus, and demand that the Assad regime keep its chemical and biological weapons warehoused and under strict control.
But the vote, which takes place amid deadlock at the Security Council over the Syrian crisis, was overshadowed by the resignation of former UN chief Kofi Annan as the joint UN-Arab League envoy to Syria after his peace proposals failed.
The anti-Syria resolution is expected to easily pass in the 193-member General Assembly after its Arab sponsors removed two key provisions in the original draft - a demand that President Bashar Assad resign, and a call for other nations to place sanctions on Syria over its civil war.
Meanwhile, UN peacekeeping chief Herve Ladsous told the Security Council that UN military observers in Aleppo are seeing "a considerable build-up of military means, where we have reason to believe that the main battle is about to start".
The rebels have commandeered tanks and are bringing them into combat as Syrian warplanes strike back.
"Even in Damascus, I was there a few days ago, one could hear explosions regularly, interminably," he said after briefing the council.
UN Secretary-General Ban Ki-moon urged restraint on all sides, saying: "Both the government and the opposition forces continue to demonstrate their determination to rely on ever-increasing violence."
But in the General Assembly, diplomats reviewed a draft resolution by Saudi Arabia that focused all its indignation on Assad's government, military forces and the militias that enforce the regime.
It denounced attacks on children as young as nine by the Syrian government, military intelligence services and militias, railing against "killing and maiming, arbitrary arrest, detention, torture and ill-treatment, including sexual violence, and use as human shields".
In a sign of how quickly the situation can change, the resolution that began to circulate on Monday reaffirmed its support for Mr Annan, though he had resigned as special envoy on Thursday.
The original draft had called for Assad to resign, highlighting an Arab League call on July 22 for "the Syrian president to step down from power, in order to facilitate a peaceful political transition".
That call for regime change appalled many UN members when the draft was discussed in private with regional groups on Tuesday. Syria was one of the original 51 members of the United Nations in 1945.
Now, the world body set up to protect nation-states from invasion and foreign domination was about to demand a change in government from one of its charter members.
Russia and China opposed the draft, as expected. Both countries have cast a double-veto in the Security Council three times to kill resolutions that could have opened the door to sanctions on Syria, or even military intervention.
But the Saudi sponsors of the draft resolution were taken aback when General Assembly nations including Brazil, India, Pakistan, South Africa and Argentina choked on the regime change and sanctions paragraphs in the draft.
Iraq suffered for years under UN sanctions intended to pressure Saddam Hussein, but which only afflicted the Iraqi people, until he was toppled in 2003 by the United States, Britain and their allies in the Gulf War.
With the tougher language, the Saudi resolution was in danger of falling below 100 votes in the 193-member Assembly, and would be seen as weak and lacking moral authority. General Assembly resolutions are unenforceable. The last General Assembly resolution on Syria, in February, had 137 votes in favour.
The draft was quickly pulled back and the regime change and sanctions provisions were stricken out by Wednesday. The revised resolution still demands that the Syrian army stop its shelling and helicopter attacks and withdraw to its barracks.
It takes a swipe at Russia and China by "deploring the Security Council failure" to act.
The resolution condemns the increasing Syrian military reliance on heavy weapons, including tanks and helicopters, and "failure to withdraw its troops and heavy weapons to their barracks" in line with a set of proposals by UN/Arab League envoy Mr Annan.
It backs Mr Annan's "demand that the first step in the cessation of violence has to be made by the Syrian authorities, and therefore calls upon the Syrian authorities to fulfil immediately their commitment to cease the use of heavy weapons and complete the withdrawal of their troops and heavy weapons to their barracks".