Russia and Syria have issued a joint statement calling on the US to remove its troops from Syria.
"We ... call on the United States, whose military units are on Syrian territory illegally, to leave the country," said the joint statement.
Earlier this month, the US said it would leave about 400 US troops in two different regions of Syria.
Both countries also want the US to allow people from a refugee camp near the Jordanian-Syrian border to be evacuated by Russian and Syrian troops.
"We urge the United States to release illegally detained residents of the Rukban camp to ensure their right to free (without payment) access to places of permanent residence."
The statement, released by the Russian Ministry of Defence, said that Russian and Syrian forces would relocate people in the Rubkan area and guarantee them safe passage to their places of permanent residence.
Rukban is inside a "deconfliction zone" set up by US forces but Damascus claims US troops are occupying the Syrian territory and providing a safe haven for rebels.
The zone is meant to shield US troops at the Al-Tanf military base near the al-Tanf border crossing, close to the Iraq-Syria and Jordan-Syria borders.
"The command of the US group in the al-Tanf zone interferes the exit, moreover, misleads the refugees about the inability to leave the camp, spreads rumours, that on the territory controlled by the Syrian government, they will be devastated, forced into conscription and arrested," said the statement.
The military base also allows the US to be close to a supply route where Iranian weapons enter Syria from Iraq.
Back in 2018, the UN mission in Syria and the Syrian Red Arab Cresent (SARC) said the "overall humanitarian situation inside the Rukban camp is at a critical stage".
In the past few years, tens of thousands of people fled to the camp from Islamic State-held parts targeted by Russian and US-led air strikes.