Russia on Wednesday accused the US and Syrian opposition of blocking the evacuation of a refugee camp in southern Syria, where the UN has described conditions as "critical".
The Russian army called the isolated Rukban camp in a US-controlled desert near the Jordanian border a "death camp".
According to Moscow, a UN-led evacuation operation is scheduled to begin on September 27 to transfer the camp's thousands of refugees to regime-controlled territory. But Russian army general Mikhail Mizintsev told a press conference the evacuation was "on the verge of collapse," blaming it on opposition under US control, AFP reported.
According to the Russian army, the opposition refused to ensure the safety of evacuation convoys.
Rights groups have warned that civilians returning to government-led territory have faced detention and conscription.
The UN said it sent aid to the Rukban camp this month, the first such delivery since February.
According to the UN, some 12,700 people remain in the camp which is near a base used by the US-led coalition.
Syria and Russia said in February they had opened corridors out of the camp, calling on residents to leave.