Syrian rebels say that the US will not help them fight a Russian-backed offensive by Syrian government forces.
In a message from Washington to the heads of the Free Syrian Army groups, the US government said “you should not base your decisions on the assumption or expectation of a military intervention by us”.
The message also told the rebels that the decision on how to face the Syrian army’s military action was up to them.
“We in the United States government understand the difficult conditions you are facing and still advise the Russians and the Syrian regime not to undertake a military measure that violates the zone,” the message added.
The words seem to go against earlier warnings from the US that Syrian President Bashar al Assad and his Russian allies would face “serious repercussions” if they violated a “de-escalation” zone that was agreed by the US and Russia last year.
The US has supported the FSA with weapons and salaries during the seven-year war under a programme run by the CIA.
But it is believed this stopped after US president Donald Trump ended the programme.
While Syrian forces had used artillery and rockets to pound the country’s south west, Russian warplanes had been mostly absent until Saturday when they hit an opposition-held town in the area.
Mainstream rebel groups would struggle against a more involved Russia and the loss of southern Syria would be a major blow for them.