BEIRUT — Syria's military said Monday it has regained control of 98 percent of eastern Aleppo, as government forces close in the last remaining sliver of a rebel enclave packed with fighters as well as tens of thousands of civilians.
A medical administrator said he and the staff of the last remaining clinic in rebel-held districts were huddled in a shelter as Syrian government forces pushed in. "Those killed and wounded are left on the streets," Mohammed Abu Rajab said.
Syrian President Bashar Assad's troops and allied militias are on the verge of victory in Aleppo, the country's largest city and onetime commercial capital, which has been divided since 2012.
A Syrian rebel spokesman in contact with fighters in the city called the collapse "terrifying." Bassam Haj Mustafa, a senior member of the Nour el-Din el-Zinki group, said "they are doing their best to defend what is left."
A U.S. official said Russia, a key ally of Assad, has refused an American proposal for a temporary halt to the fighting to allow the safe departure of those remaining in rebel-held areas. The proposal came during weekend talks in Geneva between U.S. and Russian experts that had been billed as 11th hour attempt to ease Aleppo's endgame. The official was not authorized to discuss the matter publicly and so spoke on condition of anonymity.
Osama Abo Zayd, a legal adviser to the Free Syrian Army rebel coalition, said some fighters had agreed to evacuate but that the Russians had demanded that all militants surrender, something he said was impossible.
"This pushes us to fight to the last breath despite what we have to face," he said.
The loss of Aleppo would mark the greatest defeat for the rebels since the conflict began in 2011. The insurgents still control the northwestern Idlib province as well as scattered patches of territory elsewhere in the country.
Earlier on Monday, Syrian troops and allied Shiite militiamen from Lebanon, Iraq and Iran captured Sheikh Saeed, a sprawling neighborhood in eastern Aleppo. The military also claimed to have retaken al-Fardous, one of the most populous districts.
Rami Abdurrahman, head of the Britain-based Syrian Observatory for Human Rights, said the rebels still control around 7 percent of eastern Aleppo. His group relies on a network of activists inside Syria.
"The situation is very, very critical," said Ibrahim al-Haj, a member of the Syrian Civil Defense, volunteer first responders who operate in rebel-held areas. He said he has been seeking shelter for himself and his family, fearing clashes or capture by the government.
Tens of thousands of civilians have fled to government-held western Aleppo since the offensive began last month, but tens of thousands of others are believed to have remained in the city's east.
A rebel fighter from inside Aleppo, speaking on condition of anonymity for fear of reprisals, said most of the remaining civilians have massed in two or three neighborhoods, raising the specter of mass casualties if they are targeted by airstrikes or artillery. He said the collapse of Sheik Saeed meant the loss of the enclave's last mill and grain warehouse.
A map distributed by the Syrian military shows rebel control limited to a small sliver of territory spread across six neighborhoods in the city center.
Shafak, a Turkey-based Syrian organization that supported a number of medical facilities in Aleppo, said all eight of its ambulances have been destroyed. It said 47 of its 57 staff are stuck in rebel-held areas and that it has lost contact with most of them.
The offensive began on Nov. 26, and followed an intensive aerial campaign that knocked out most of the medical facilities in eastern Aleppo, which has been besieged by government forces since July.
State TV has shown daily footage of hundreds of civilians pouring into government-held western Aleppo, which can only be reached through monitored crossing points. The U.N. human rights office says it has received reports of hundreds of men going missing after crossing into government areas.
Associated Press writers Albert Aji in Damascus, Syria, and Jamey Keaten in Geneva contributed.