AMMAN: Pro-regime forces in the eastern Syrian desert are advancing towards a coalition base near the Iraqi-Syrian border, while a US military spokesperson tells Syria Direct that the American-led forces will "defend themselves" from any further encroachment.

“If pro-regime forces move further south or east from their current positions, this will be considered a threat,” an unnamed US military spokesperson told Syria Direct by email on Sunday.

“Coalition forces will defend themselves.”

The Syrian Arab Army (SAA) and its allied militias are currently mobilizing and advancing along two fronts towards Syria’s southern border with Iraq in the Syrian Badia, a sparsely populated desert region spanning central and eastern Syria.

The advances are moving in the direction of the coalition-operated a-Tanf military outpost several kilometers from the Iraqi-Syrian border, where the military spokesperson said US and other coalition members are currently “training and advising vetted partner forces” battling the Islamic State (IS).

A member of a pro-regime militia stands near a vehicle in the Syrian Badia. Photo Courtesy of the a-Sheyukh Media Center

A video released last week also appeared to show US ground forces participating in fighting alongside rebels against the Islamic State.

While the regime has not officially explained its motives behind its recent offensives in southeastern Syria, retaking strategic border areas with Jordan and Iraq could re-establish commerce and ground transportation that stopped years ago due to the war.

In regime-controlled a-Suwayda province along Syria’s southern border with Jordan, an estimated 110km west of a-Tanf, SAA forces and their allies captured the Zalaf Dam and several small settlements east of a-Suwayda from US-backed rebels over the weekend.

That advance stalled on Monday, Muhammad Adnan, a spokesman for the US-backed rebel faction Jaish Ahrar al-Ashair told Syria Direct. However, "the battle continues until this very moment," the rebel spokesman added.

Meanwhile, pro-regime, Iranian-backed militias advanced southwards from the government-held eastern Qalamoun area on Sunday, taking territory from US-backed rebels in the Badia amid ongoing clashes.

While fighting continues in the Badia north of a-Tanf, the small number of rebel fighters, along with the wide desert landscape make it difficult to accurately track who controls the land, a rebel commander with Maghawir a-Sahraa told Syria Direct on Monday.

Also on Monday, the Free Syrian Army announced “Badia Volcano,” a campaign to “cleanse the Badia of Iranian and foreign militias.”

‘A show of force’

On Thursday, days before the latest regime advances to the west and north of a-Tanf, coalition warplanes attacked a convoy of “tanks, armored vehicles, artillery and technical vehicles” advancing from government-controlled territory towards the outpost, the US military spokesperson told Syria Direct via email.

The warplanes struck a tank and “construction equipment being used to build a fighting position,” the spokesperson said. Russia attempted to "dissuade" the advance prior to the strike, but was unsuccessful, the source added.

The US-led coalition’s primary goal in southern Syria is to engage IS forces and find an “entry point” into IS-controlled Deir e-Zor province in central and eastern Syria, Syria Direct reported last week.

Last week, US-backed rebels with Maghawir a-Thawra (MAT) clashed with IS along the provincial border between Deir e-Zor and Homs provinces.

Sources within the rebel faction told Syria Direct that US Special Forces directly participated in battles with IS 80km south of al-Bukamel, a small IS-controlled town at the southern base of the Euphrates River.