Damascus: The USinfo-icon has threatened Damascus with "firm and appropriate measures" if the Syrian armyinfo-icon launched an offensive against rebels in the  strategic province they hold near the border with the Israeli-occupied Golan Heights.

In a statement released on Friday, US State Department spokeswoman Heather Nauert expressed concerns about the upcoming operation in southwestern Dara'ainfo-icon province which is in the rebel control since 2015.

The warning came two days after the so-called Syrian Observatory for Human Rightsinfo-icon (SOHR) reported that the Syrian troops were moving into Dara'a after liberating all remaining terrorist-held areas near the capital, Damascus.

The battle for Damascus ended this week with an offensive against the Daesh or ISIS group among the ruins of a former Palestinian refugee camp in the southern suburbs after other terror groups were defeated in a nearby enclave.

The armed opposition is now relegated to Idlib province in the north near the Turkish border and Daraa in the south near the Israeli border. On Friday, Syrian aircraft dropped leaflets in the northern districts of Dara'a, warning rebels to lay down their weaponsinfo-icon or face an offensive there.

"The men of the Syrian army are coming. Take your decision before it is too late," the leaflets read, according to the Syrian Central Military Mediainfo-icon's website.

"Syrian forces are now stationed on the edges of Dara'a province," Observatory head Rami Abdel Rahman said. "The goal is a broad offensive, should the rebels reject a negotiated pullout as was the case in Eastern Ghouta."

The recapture of Dara'a is highly important because it borders the occupied Golan Heights which Israel has used to treat wounded rebels for years.

The territory's return to the Syrian government control would cut the much-reported collaboration between Israel and militants and deal a blow to Tel Aviv's plans to annex the Golan Heights. 

In a statement released Friday, the US State Department said it was concerned by reports that Syrian army and allied forces were preparing for an operation in southwestern Syriainfo-icon. It warned the Syrian government against "any actions that risk broadening the conflictinfo-icon."

Analysts say Syrian army advances are upsetting to US plans in the Arab country where it has deployed about 2,000 troops to carve out a statelet in the country's north with the help of Kurdish militants.

With Syria's military gains gathering momentum, the US has already stepped up its attacks on army positions under numerous pretexts. 

On Thursday, Syrian state media reported that the US struck Syrian army positions in eastern Syria, but the US military denied knowledge of it. 

"Some of our military sites between Albu Kamal and Humeima were exposed at dawn today to aggression launched by US coalition jets," state news agency SANA reported, citing a military source.

SANA said the strikes came within 24 hours of a Daesh attack on Syrian army positions in the same region, where the remnants of terror group are fighting government forces to the west of the Euphrates.

US-ISRAELI WORRY

The impending attack on Da'ara which is under rebel control since February 2015 is causing worry in Washington and Tel Aviv because the this region is important for the direct Syrian front against Israel. Syrian army here is backed by the Iranian Quds forces and Hizbollah.

Developments in the Daraa district will have far reaching consequences for the future of Syria and a victory by the Iranian-led axis will not be comfortable for Israel.

Stabilizing a front controlled by the axis from the Daraa district will therefore help construct a new equation vis-a-vis Israel that will in effect unify this territory from the Syrian Hermon to southern Lebanoninfo-icon, and give Hizbollah strategic depth.

The opposing sides attribute great importance to the results of the campaign and are preparing for long, difficult fighting before there might be any decision.