Eight hundred civilians - including at least 177 children - have been killed since Russia-backed regime forces launched an assault on the besieged enclave outside Damascus on Feb 18, the Syrian Observatory for Human Rights said in its latest death toll.
The group said on Tuesday that ground units loyal to President Bashar al-Assad had taken control of more than 40 percent of the district.
Russian Federation recently offered safe passage for Syrian opposition fighters in Eastern Ghouta.
On Monday the first humanitarian aid convoys since November rolled into rebel-held areas in the Damascus suburbs to deliver medical supplies, food and nutritional supplements to besieged civilians. Ali al-Za'tari, asked the government to commit to a ceasefire on Thursday to allow more aid in.
"We did not find any indication that the attack was meant to hit either civilians or a civilian building but that the USA forces had enough time and resources available, that they should have been able to take additional precautions that may have led to the air strike being called off or delayed", Pinheiro said.
"The Syrian government and its ally Russian Federation is pummeling the area with airstrikes and shelling attacks, as it makes a concerted effort to take back control of these towns and villages near Damascus", Ruth reports.
The mission on Monday to the area known as eastern Ghouta was cut short after the government shelling escalated while the aid workers were still inside, calling into question future aid shipments to the encircled region, the last major opposition stronghold near the capital.
The ministry highlighted that the only areas where the provisions of Resolution 2401 are being largely neglected are those controlled by the US: The people of Raqqa and the Rukban refugee camp are still being denied humanitarian aid despite the US-occupied At-Tanf being located in close proximity to the areas, the report outlined.
The United Nations resident and humanitarian coordinator in Syria Ali al-Za'tari sent the letter to Syrian Deputy Foreign Minister Faisal Mekdad on Tuesday according to a copy seen by Reuters. It says the rebels are also free to leave the enclave with their weapons and families unhindered.
"It shows what a farce this de-escalation zone has become", Nauert said. "The people sit with multiple families, with thousands of families in basement shelters", he said.
Turkey views the main Kurdish militia in Afrin as an extension of the Kurdish insurgency within its own borders.
Civilians gather near a convoy of Syrian Red Crescent vehicles Monday in Douma in eastern Ghouta, a suburb of Damascus, Syria.
Iyad Abdelaziz, a member of the Douma Local Council, says nine aid trucks had to leave the area after government shelling and airstrikes intensified in the evening.
Regime troops and allied forces have advanced rapidly across farmland in the east of the enclave in recent days, the Observatory said.