A separate truce for southern Syria, brokered by the U.S. and Russia, is meant to help allay growing concerns by neighboring Jordan and Israel about Iranian military ambitions in the area, including fears Tehran plans to set up a disruptive long-term presence there. Such apprehensions were stoked by recent movements of Shiite militias – loyal to Iran and fighting alongside Syrian government forces – toward Jordan's border with Syria, and to another strategic area in the southeast, close to where the two countries meet Iraq.

Syria's neighbors suspect that Iran is pursuing a broader agenda, including carving out a land route through Syria that would create a territorial continuum from Iran and Iraq to Lebanon.

The southern Syria truce is separate from so far unsuccessful efforts by Russia, Turkey and Iran to set up "de-escalation zones" in Syria, including in the south.

The country has repeatedly said it would not allow Iran to set up a permanent presence in Syria.

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