The United States says it is "deeply concerned" about a surge in attacks by the Syrian government and its allies on a rebel-held enclave near the capital, Damascus.
The cessation of violence in the Eastern Ghouta region "must begin now," State Department spokeswoman Heather Nauert told reporters on February 20, denouncing what she called the "siege and starve tactics" of forces loyal to President Bashar al-Assad.
The British-based Syrian Observatory for Human Rights says air strikes, rocket fire, and shelling has killed at least 250 people in the besieged region in two days.
Meanwhile, factions in Eastern Ghouta fired mortars at eastern districts of Damascus, killing at least six people there, according to Syrian state media.
The UN's humanitarian coordinator for Syria, Panos Moumtzis, said that six hospitals had been hit in Eastern Ghouta in the past two days, adding that at least three were out of service and two were partially functioning.
The UN has warned that the humanitarian situation of civilians in the region was "spiraling out of control" and called for a cease-fire to allow humanitarian aid to be delivered and hundreds of critically sick and wounded patients to be evacuated.
Nearly 400,000 people live in Eastern Ghouta, a pocket of satellite towns and farms under government siege since 2013, the world body says.