The Syrian Observatory for Human Rights monitoring group says 800 civilians have been killed by government bombing and shelling.
Airstrikes continued Tuesday. The opposition's Syrian Civil Defense search-and-rescue group reported at least nine people were killed in airstrikes on the town of Jisreen.
Gen Yevtushenko said the Russian military were prepared to evacuate more than a thousand sick and wounded persons, but the militants disrupted this opportunity.
Pro-government forces appeared to be approaching the central towns of Misraba and Mudayrah from the east, potentially splitting the enclave in two.
Russian warplanes have taken part in the eastern Ghouta operation, and the White House has accused Russia of complicity in the killing of civilians there.
Olwan said Wednesday that rebels had plugged their defensive lines after they crumbled in the early days of the assault.
The state-affiliated al-Ikhbariya TV station on Wednesday broadcast live shots from the region, showing dense columns of smoke rising above the town as explosions and rockets could be heard flying overhead.
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"This month, it is Eastern Ghouta, which is, in the words of the secretary-general, hell on Earth. The Security Council needs to find a solution to stop the daily bloodbath as this is the Council's responsibility and even if Russian Federation was the one bearing the greatest political and moral iniquity, it remains everyone's responsibility along with Russian Federation".
At the United Nations, key regime backer Russian Federation presses for a negotiated withdrawal of rebel fighters and their families, like the one that saw the government retake full control of Aleppo in December 2016.
The UN Security Council last month voted for a nationwide ceasefire which specifically urged parties to the conflict to allow aid into Eastern Ghouta.
Assad said on Sunday the Syrian army would continue the push into eastern Ghouta, which government forces and allied militia have encircled since 2013.
Although 46 aid trucks entered the area on Monday for the first time since the offensive started, they had cut short their deliveries due to heavy bombardment. The offer presented to the opposition fighters did not include specifics on where they would go after leaving their positions, but it resembles several attempts in the past few months where fighters were able to relocate to other rebel-held areas and guarantees long-term immunity to fighters who accept it.
"Right now there is a huge escalation in Ghouta".
"Russia conducted 20 bombing missions in Damascus and Eastern Ghouta the week of February 24".
US officials have been warning that Turkey's offensive against USA -backed forces in Syria would affect the fight against Islamic State group.
Speaking to reporters at a news conference, Kalın said that Turkey has mobilized all efforts to get concrete results to find a solution to the humanitarian crisis in eastern Ghouta.