U.N. Chief Urges Ceasefire in Aleppo

U.N. Secretary General Ban Ki-moon appealed for a ceasefire Wednesday in the besieged Syrian city of Aleppo to allow aid to reach civilians, calling the situation "heartbreaking."

"I have been urging the Syrian authorities and Syrian armed groups, and also the coalition... to keep their promises so that we can do our humanitarian" job, Ban, on his last foreign trip as head of the U.N., told reporters in Vienna.

"What we have seen most recently in eastern Aleppo, that is really heartbreaking.

"Most of the infrastructure, hospitals, clinics, water supplies, food supplies have been cut off. This is a serious humanitarian crisis," added Ban, speaking alongside Austrian Foreign Minister Sebastian Kurz.

In the face of a blistering assault by forces loyal to President Bashar Assad, rebels were reported to have retreated Wednesday from all of Aleppo's Old City, the latest in a string of territorial losses.

After three weeks of heavy fighting, regime forces appear closer than ever to retaking all of Syria's second city and winning their most important victory yet in the civil war that began in 2011.

Rebel fighters have rejected calls to withdraw from Aleppo, which had been divided between government and opposition forces since 2012, but on Wednesday issued a joint statement calling for an "immediate five-day humanitarian ceasefire."