The United States has told Syrian rebel factions they should not expect military support to help them resist a Russian-backed government offensive.

:: The United States has told Syrian rebel factions they should not expect military support to help them resist a Russian-backed government offensive to regain opposition-held parts of Syria bordering Jordan and the Israeli-occupied Golan Heights.

A copy of a message sent by Washington to heads of Free Syrian Army (FSA) groups, which was seen by Reuters, said the US government wanted to make clear that “you should not base your decisions on the assumption or expectation of a military intervention by us”.

The United States had earlier warned Syrian President Bashar al-Assad and his Russian allies that violations of a “de-escalation” zone agreed by the United States and Russia last year would have “serious repercussions” and pledged “firm and appropriate measures.”

The toughly worded statements coming from the administration had raised the hopes of the Western-backed opposition of a possible American military intervention in the event the Syrian army’s several days long bombing campaign broadens to an all-out offensive across the southwest.

The US message also told the rebels it was left to them alone to take the right decision on how to face the Syrian army’s military campaign based on what they saw was best for themselves and their people.

“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 also said.

The United States has supported the moderate mainstream FSA faction with millions of dollars worth of arms and paid monthly salaries to thousands of rebels in the course of the seven-year war under a military aid program run by the Central Intelligence Agency.

But analysts believe the aid has dropped after US President Donald Trump decided last year to shut down the program.