BEIRUT (Reuters) - Syria’s army and its allies will keep fighting in Syria after the battle ends in Deir al-Zor province, where Islamic State has its last significant stronghold, President Bashar al-Assad said on Tuesday.

A man stands near military vehicles that belong to the Syrian army in Deir al-Zor, Syria September 21, 2017. REUTERS/Omar Sanadiki

He also indicated that he might take the war to the U.S.-backed Syrian Democratic Forces (SDF), which controls more than a quarter of Syria, by saying the war targeted those who seek to “divide and weaken states”.

His comments came after a meeting with Ali Akbar Velayati, the foreign policy adviser to Iran’s Supreme Leader Ayatollah Ali Khamenei.

“The victories against terrorist organizations, starting in Aleppo and not ending in Deir al-Zor, formed a critical strike that foiled partition projects and terrorist goals,” Assad’s office quoted him as saying.

Assad regards all the groups fighting against the Syrian state as terrorist groups.

The Syrian army, with Russian air power and Iran-backed militias, is waging an offensive against Islamic State in the eastern Deir al-Zor province, mostly on the west banks of the Euphrates River.

The SDF, an alliance of Kurdish and Arab militias, is also battling IS militants in Deir al-Zor. Backed by U.S.-led air strikes and special forces, the SDF has focused on territory east of the river, which bisects the oil-rich province.

Velayati on Friday said Syrian army forces would soon advance to take Raqqa city from the SDF and accused the United States of seeking to divide Syria by stationing its forces east of the Euphrates.

“We will witness in the near future the advance of government and popular forces in Syria and east of the Euphrates, and the liberation of Raqqa city,” he said in televised comments on a visit to Beirut.

Turkey also supports rebel groups in a pocket in northern Syria, wedged between Kurdish-controlled areas. Last month, its army began setting up observation points in Idlib province in northwest Syria under a deal with Russia and Iran.

Assad said in his meeting with Velayati that the battle would last “until the recovery of security and stability to all Syrian lands”, his office said.