NEAR AS-SUSAH, Syria - Fighters from the Kurdish-led Syrian Democratic Forces sing for courage as they ready for battle, this time for an assault on the Islamic State group's last stronghold in the country's east.
The US-backed SDF and their American advisers have been grouped on the outskirts of the village of As-Susah on the east bank of the Euphrates River in Deir ez-Zor province.
As pick-up trucks loaded with fighters of the joint Kurdish-Arab force skid along snaking dirt roads, coalition forces have been firing rounds of mortar fire and rockets at jihadist positions.
After a salvo of outgoing fire, thick columns of smoke rise from As-Susah, which along with the town of Hajin and other nearby villages make up ISIS's last enclave in eastern Syria.
"Daesh has strong fortifications. We're seeking to break the defences and bring its presence east of the Euphrates to an end," said a commander, Ibrahim al-Dairi, using an Arabic acronym for ISIS.
The SDF has been closing in on the pocket for months and it officially launched its offensive on Monday.
Heavy clashes have since killed 46 jihadists and 15 SDF fighters, according to the Syrian Observatory for Human Rights monitoring group.
The offensive "will clear remnants of (ISIS) from northeastern Syria along the Middle Euphrates River Valley toward the Syria-Iraq border", according to the coalition.
"The battle is fateful for us and for Daesh too," said Dairi, using an Arabic acronym for the jihadist group.
He expects the remaining jihadists to "fight to the death."
The SDF estimates ISIS has some 3,000 fighters in its besieged holdout, a large portion of them foreigners.
- 'Eliminate them here' -
After having declared a cross-border "caliphate" in 2014, ISIS now controls less than three percent of Syria following a string of military defeats inside the country and neighbouring Iraq.
The group once held nearly all of Deir ez-Zor, but separate offensives last year by the SDF and Russian-backed regime forces left the jihadists with a just small besieged pocket near the Iraqi border.
ISIS slogans such as "the caliphate remains" mark the walls of homes in towns and villages from which ISIS has been expelled.
A few kilometres away in the desert hills along Syria's border with Iraq, the SDF and coalition leaders are charting the offensive.
Members of the SDF gather inside a building in the village of Susah in the eastern province of Deir ez-Zor, near the Syrian border with Iraq on September 13, 2018. Photo: Delil Souleiman/AFP
"We're committed to the campaign and we will win," Zaradasht Kobani, another Kurdish commander, told AFP after speaking with fighters cleaning their weapons having just returned from the front lines.
"Even though Daesh has taken a lot of (defensive) measures... we will end its presence east of the Euphrates," he said.
"This is the last bastion for Daesh's mercenaries," Kobani said. "We will eliminate them here."
- 'Defeat terrorism' -
While ISIS leader Abu Bakr al-Baghdadi's whereabouts are unknown, the SDF believes other "major leaders" are hiding out in the pocket, according to Deir ez-Zor military council chief Ahmad Abu Khawla.
"Most of the frontline commanders in this pocket are Iraqis," he added.
The US coalition is backing up the SDF's push with artillery support and air cover.
Kobani stressed that the coalition's involvement was important for SDF morale. "We will end this campaign together," he said.
Like in other battles that the SDF has waged against ISIS, booby traps and mines planted by the jihadists pose the biggest challenge.
As artillery fire pounded jihadist positions, yellow military bulldozers worked to clear roads for fighters.
