US Warns Syrian Government Not To Advance On South

US Marine in Syria (Picture: US Department of Defense).

The US government says it will take "firm and appropriate measures" if President Bashar Assad's forces attack rebels in southern Syria.

This warning comes as the US aims to protect a ceasefire in the region. 

Last year, the US, Russia and Jordan agreed on a "de-escalation zone" in the southwest of Syria to freeze the lines of conflict. 

In a statement, the US State Department said it was concerned by reports that Assad's forces were preparing for an operation near the Jordan and Israel borders.

The State Department warned the Syrian government against "any action that risk broadening the conflict". 

Both the US and Israel are increasingly concerned about Iranian military activities in Syria, in support of the Assad regime. 

Israel says it does not want Iranian forces close to the nearby occupied Golan Heights.