Syrian warplanes again pounded Aleppo's last rebel-held districts today, as the United States said American and Russian officials would meet in a bid to save the city from "complete" destruction.
With the fighting resuming after a brief respite, the UN General Assembly demanded an immediate ceasefire and urgent aid deliveries, in a resolution adopted by a strong majority.
US officials will meet tomorrow with their Russian counterparts in Geneva to try to stop Aleppo "being absolutely, completely destroyed", US Secretary of State John Kerry said.
He was in Paris for a meeting of foreign ministers from the Western and Arab backers of Syria's weakened opposition, also tomorrow.
Kerry was not upbeat about the chances of success, however, as key regime ally Russia vowed that the assault would not end until rebels leave Aleppo.
"I know people are tired of these meetings, I'm tired of these meetings," Kerry said.
"But what am I supposed to do? Go home and have a nice weekend... While people are dying? Sit there in Washington and do nothing?"
Government strikes had halted briefly from yesterday night, when Moscow announced a pause in the regime offensive to allow the evacuation of civilians, although shelling did not cease.
Syria's army is three weeks into a battle to retake east Aleppo from rebels who are now confined to just a few neighbourhoods in their former bastion.
The city's loss would be the biggest blow for the rebels in Syria's nearly six-year-old war, which has killed more than 300,000 people and displaced over half the country's population.
Tens of thousands of civilians have fled east Aleppo in recent weeks, although the United Nations said today it had received reports that rebels had blocked some from leaving.
It also expressed concern about reports that hundreds of men had gone missing after fleeing to government-held territory.
The Syrian Observatory for Human Rights, a Britain-based monitor, reported at least a dozen air strikes on rebel-held neighbourhoods today afternoon.
Artillery fire had continued throughout yesterday night and into today after Moscow's announcement, the monitor and an AFP correspondent in east Aleppo reported.
Syria's army has captured around 85 percent of east Aleppo, with rebels and remaining civilians confined to a shrinking space in increasingly grim conditions.
East Aleppo has been encircled by the regime since mid-July, with international aid provisions exhausted and remaining food supplies dwindling even before the government assault began in mid-November.
The AFP correspondent said fleeing civilians had seen bodies in the streets of one neighbourhood because the intensity of the bombardment made it too dangerous to retrieve the dead.