The UN humanitarian affairs chief says the number of Syrians living under siege has more than doubled in the past year to nearly 1 million people.
Stephen O'Brien told the UN Security Council on November 21 that the number of besieged people rose from 486,700 to 974,080 people.
O'Brien said the sieges were mostly perpetrated by Syrian government forces against civilians.
"Civilians are being isolated, starved, bombed, denied medical attention and humanitarian assistance in order to force them to submit or flee,"he said.
O'Brien strongly criticized President Bashar al-Assad's government for its failure to defend all Syrians and for invoking national sovereignty "to bomb its own people."
O'Brien again urged strong action from the Security Council to back its resolutions calling for an end to attacks on civilians, humanitarian aid access, and a lifting of sieges.
"Without strong backing from each of you, red lines will be crossed again and again; international humanitarian law will be trampled on; war crimes will be committed,” O’Brien said.