The Syrian Observatory for Human Rights said on Thursday of the 601 civilians, killed in mostly air strikes, 147 were children.
But not one of the battered region's 400,000 residents had left to board buses provided by the regime by late Wednesday.
Russia, a strong ally of Syrian President Bashar al-Assad, has called for daily five-hour local ceasefires to establish what it calls a humanitarian corridor so aid can enter the enclave and civilians and wounded can leave.
The Eastern Ghouta truce falls far short of a broader 30-day ceasefire Russian Federation agreed to at the UN Security Council on Saturday but which has yet to take effect, and has inspired little trust among the besieged enclave's 400,000 residents.
On Saturday, the UN Security Council adopted a resolution calling for a 30-day ceasefire in Syria.
The ceasefire will be applicable from 9 am to 2 pm.
He insisted the five-hour daily pauses would be fruitful, "if the bandits who control East Ghouta so allow". Guterres demanded an immediate ceasefire in Eastern Ghouta.
Syrian air defences shot down an Israeli F-16 earlier this month as it returned from a bombing raid on Iran-backed positions in Syria.More news: Shots fired at north Georgia high school, teacher in custody
More news: Illinois River Flooding In Cherokee County
More news: Redrawn Map Spells Big Changes For Congressional Districts In Philly Region
"The terrorists are impeding those who want to cross, either by putting pressure on them or by firing on the humanitarian corridors", the military officer said, speaking on condition of anonymity.
On February 24, the United Nations Security Council voted in favour of a 30-day truce, which was violated only hours later. Fourteen of the dead, including five children, were pulled from the rubble on Tuesday after being killed in the past two days, said the Observatory. But the evacuation of civilians from Eastern Ghouta has not taken place so far, the official admitted. But the truce was marred by violence, with Moscow and Damascus accusing armed groups of shelling the purported humanitarian corridors and keeping the population hostage.
"Shells even crash into the grounds of the Russian embassy and the economic mission". Are we going to tolerate this indefinitely? "No, of course not", he said.
He made the comments shortly before Russian Foreign Minister Sergei Lavrov, addressing the UN-sponsored disarmament conference in Geneva, asserted that Syria had eliminated its chemical-weapons stockpiles and placed them under global control. "Mogherini said in the letter, which was also sent to all 28 European Union foreign ministers and to the secretary-general of the United Nations Antonio Guterres, that a ceasefire would give a chance for UN-led peace talks to make progress". "Under global humanitarian law, humanitarian corridors are things which need to be well planned and must be implemented with the consent of parties on all sides, not only with one side", she told AFP.
Lowcock said convoys are ready to go to 10 besieged and hard-to-reach locations including 45 trucks with aid for 90,000 people in Douma in eastern Ghouta.
"This is cynical, callous and in flagrant defiance of the demands of [Resolution] 2401", said USA envoy Kelley Currie.
While diplomats at the United Nations wrangled over implementing the ceasefire, the regime was making a push for territory on the fringes of the besieged enclave. State media said the rebels inside Ghouta are preventing civilians from leaving, an accusation they deny. "More bombing. More fighting".