US President Donald Trump and British PM Theresa May blame Russia and the Assad regime for the appalling humanitarian situation in Syria's eastern Ghouta, the premier's office announced Sunday.
In a phone call, the two leaders discussed the violations against civilians and "heart-breaking human suffering" in the rebel-held enclave near Damascus.
In a statement, May's office said, "They agreed it was a humanitarian catastrophe, and that the overwhelming responsibility for the heart-breaking human suffering lay with the Syrian regime and Russia, as the regime's main backer," May's office said.
The statement called on Moscow and other parts with influence on the course of actions in Syria to immediately cease violence and protect civilians, the statement read.
The Assad forces now seize control of more than a quarter of Eastern Ghouta, according to the Britain-based Syrian Observatory for Human Rights.
This comes after 15 days of airstrikes, artillery fire and rocket attacks on opposition forces in the enclave. Reports confirm more than 640 civilians were killed.
The United Nations Security Council unanimously voted for a 30-day truce. But the Syrian regime ignore it.
The UN said it would deliver humanitarian aid to the Eastern Ghouta enclave on Monday.