BEIRUT -- U.S.-backed Syrian fighters started an offensive against the Islamic State group in eastern Syria along the border with Iraq on Saturday, bringing them into a race with government forces marching in the same direction against the extremists in their last major holdout in the war-torn country.
The dueling battles for Deir el-Zour highlight the importance of the oil-rich eastern province, which has become the latest focus of the international war against the Islamic State, raising concerns of an eventual clash between the two sides.
The U.S.-trained Deir el-Zour Military Council said it was calling its operation Jazeera Storm, after the familiar name for northeast Syria. The Military Council is a part of the predominantly Kurdish Syrian Democratic Forces, which enjoys broad U.S. military support. The Syrian Democratic Forces are the U.S.'s primary ally in the fight against the Islamic State in Syria.
The race to reach the Iraqi border will shape future regional dynamics, determining whether the United States or Russia and Iran will have more influence in the strategic area once the extremist group is defeated.
[THE ISLAMIC STATE: Timeline of group’s rise, fall; details on campaign to fight it]
Iran has been one of President Bashar Assad's strongest backers since the crisis began in March 2011 and has sent thousands of Iranian-backed fighters and advisers to fight against insurgent groups trying to remove him from power.
The U.S.-backed fighters are up against a huge challenge to reach Deir el-Zour, especially while they are still fighting to liberate Raqqa from the Islamic State. Three months into the battle, they have liberated around 60 percent of the city, and much more difficult urban fighting still lies ahead.
This week, Syrian troops and their Iranian-backed allies reached Deir el-Zour, breaking a nearly three-year-old Islamic State siege on government-held parts of the city in a major breakthrough in their offensive against the militants. In a victory statement, the Syrian military said Deir el-Zour will be used as a launching pad to liberate the remaining Islamic State-held areas along the border with Iraq.
Pro-government forces broke the siege of the city's airport Saturday, state media reported.
The troops' arrival to Deir el-Zour city brings Syrian forces and their allies a step closer to controlling the oil-rich eastern province and its capital bordering Iraq, a major boost for Tehran's growing influence in the area. The region has some of Syria's largest oil fields, whose revenue is vital to the state's dried coffers.
Syria's military command announced Saturday that they had captured the province's Taym oil field from Islamic State militants.
Washington has been determined to block the formation of an "Iranian corridor" -- of Shiite-controlled land stretching from Tehran to Damascus -- and for months has been eyeing the area southeast of Raqqa near the Iraqi border.
U.S.-backed Syrian rebels had been gathering in Tanf in southeastern Syria to march toward Deir el-Zour, but their plans were disrupted in June when Syrian troops reached the border with Iraq, obstructing their path. The only way left for the Syrian Democratic Forces to enter the eastern province appears to be from the northeastern province of Hassakeh, where Syrian activists say the U.S.-backed fighters have been gathering and stepping up preparations for an attack.
Syrian Democratic Forces officials say the timing of Operation Jazeera Storm is not related to government forces reaching the Deir el-Zour earlier this week, and was planned months in advance.
"Deir el-Zour is a main connection point and a very important geographic area," said Syrian Kurdish official Nawaf Khalil, who is in Germany but frequently visits northern Syria. He said the battle for Raqqa requires fewer fighters now than it did in its earlier stages.
The U.S.-led coalition fighting Islamic State militants said in an email to The Associated Press that the Syrian forces "will decide when the conditions are right for an offensive."
Asked about concerns of a possible clash between the Syrian Democratic Forces and Syrian troops, the coalition said: "We urge all forces to concentrate their efforts on our common enemy [Islamic State]."
Washington has welcomed Syrian troops' fight against Islamic State. Both the U.S. and Russia have an interest in avoiding a clash between the Syrian Democratic Forces and Syrian forces and may devise a strategy that will allow both sides to share control of the vast province.
U.S. officials have suggested they are not seeking a confrontation with Assad's forces.
"We are in the killing-ISIS business. That is what we want to do, and if the Syrian regime wants to do that ... and show that they are doing just that in Abu Kamal or Deir el-Zour or elsewhere, that means that we don't have to do that in those places," said coalition spokesman Col. Ryan Dillon in June referring to a town on the Iraqi border, and using an acronym for Islamic State.
U.S. Defense Secretary James Mattis said last month during a visit to the Middle East that the Middle Euphrates River Valley will soon be liberated, as militants take hits from both sides of the valley that bisects Iraq and Syria.
"You see, ISIS is now caught in between converging forces," Mattis said.
Information for this article was contributed by Sarah El Deeb, Philip Issa and Albert Aji of The Associated Press.
A Section on 09/10/2017