Regime backer Russian Federation last week announced daily five-hour "humanitarian pauses" in Eastern Ghouta.
"All of this blood is flowing in Syria and if I could ask anything it would be for the UN Security Council, its permanent members and the United Nations to stir their feelings, if they have feelings, and issue a real decision to stop the killing".
The office of French President Emmanuel Macron says that he and UN Secretary-General Antonio Guterres are extremely anxious about the continued violence in Eastern Ghouta despite the ceasefire resolution.
The Syrian Observatory for Human Rights said barrel bombs - crude, improvised munitions that cause indiscriminate damage - were used, including on the town of Hammuriyeh, where 10 people were killed.
Regime forces dropped leaflets on Eastern Ghouta before the offensive on Saturday night, informing residents of safe spaces, humanitarian corridors and medical points. The enclave is an agricultural region about the size of Manchester in the UK. The official said preparations are underway to deliver food to civilians in the besieged area.
"There is hardly any life there".
The UN Security Council demanded a 30-day countrywide ceasefire a week ago, but this has failed to take effect.
In a statement, it accused Syrian President Bashar al-Assad and Russian Federation of waging a "scorched earth" campaign.
Meanwhile, violence in the enclave rumbled on, including reports of chlorine gas attacks last week that were condemned by the White House.
Mr Assad said civilians would still have "the possibility" to evacuate the enclave, while denying there was any contradiction between a truce and ongoing fighting. He claimed Western accusations about the use of chemical weapons were an excuse to attack the Syrian army.
It was unclear when the USA proposal, or a separate Russian draft resolution, on the Syrian chemical inquiry, would come to a vote. Moumtziz also expressed concern about the situation in Afrin, a Kurdish region that has been under Turkish assault since January, saying there were "disturbing reports" on civilian deaths and injuries, and restrictions on civilian movement.
The regime's ground and air attacks continued on civilians in the opposition-hold area near capital Damascus despite decisions to implement a ceasefire made separately by Russian Federation and the UN Security Council.
In the town of Hazeh, rescuers working with rudimentary equipment were painstakingly hoisting buckets of gravel from a basement where they feared up to 21 were buried alive by a strike on 20 February. "There's destruction everywhere", said 35-year-old Abu Khalil, carrying a little girl in his arms wounded on the cheek. "I found the building collapsed and until now I haven't found my daughter nor her husband's family".