The US has warned Syrian rebels in the south-west of the country they should not expect military support to help them resist a major government offensive.

The message from Washington comes as Russian jets struck an opposition-held town on Sunday in the first air cover provided by Moscow to an expanding Syrian army offensive in the strategic area bordering Jordan and the Israeli-occupied Golan Heights.

The US message sent to heads of the Free Syrian Army said Washington wanted to make clear that “you should not base your decisions on the assumption or expectation of a military intervention by us”.
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The Syrian army began ramping up its assault last week in order to recapture the area.

https://www.theguardian.com/world/2018/jun/24/youre-on-your-own-us-tells-syrian-rebels-as-assad-goes-on-offensive