WASHINGTON — The United States on July 28 rebuked as a “demand for surrender” a Russian Defense Ministry announcement of “humanitarian corridors” for civilians and unarmed rebels to leave rebel-held eastern Aleppo. But despite the US criticism, Syrian opposition members and Syria analysts said that Aleppo is steadily falling to the Syrian regime, even as US-Russian negotiations on deeper cooperation in Syria continue.

Syrian government forces, backed by Russia, have in recent weeks nearly surrounded rebel-held eastern Aleppo and cut off its main supply route, Castello Road, causing a humanitarian crisis for the estimated 300,000 people living in the almost besieged area.

But while the United Nations has called for a 48-hour “humanitarian pause” in Aleppo to bring in humanitarian aid, Russia’s Defense Ministry on July 28 instead announced a plan in coordination with the Syrian regime to let residents and unarmed rebels leave the area.

“A tough humanitarian situation has developed in the city of Aleppo and its suburbs,” Russian Defense Minister Sergei Shoigu said July 28. Russia, together with Syrian authorities, will open three humanitarian corridors, for civilians and unarmed rebels to leave, he said. A fourth corridor for armed rebels is also being set up, he said.