Iraqi forces announced the launch of a major operation on Thursday to flush remaining ISIS militants out of the western desert bordering Syria. "The Iraqi army, the federal police and units from the Popular Mobilization Forces this morning began clearing the Al-Jazeera region straddling Salaheddin, Nineveh and Anbar provinces," the head of Joint Operations Command, General Abdelamir Yarallah, said in a statement. "The objective behind the operation is to prevent remaining ISIS groups from melting into the desert region and using it as a base for future attacks," said army colonel Salah Kareem. The arid, sparsely populated wastelands between the Tigris and Euphrates rivers are the last refuge of the militants in Iraq after troops ousted them from both valleys and all urban areas. The regions dry valleys, the oases and steppes make up around four percent of national territory, Hisham al-Hashemi, an Iraqi expert on ISIS, told AFP last week. Iraqi army commanders say the military campaign will continue until all the frontier with Syria is secured to prevent ISIS from launching cross border attacks. "We will completely secure the desert from all terrorist groups of ISIS and declare Iraq clean of those germs," said army Brigadier General Shakir Kadhim. "After the operation has ended, we will announce the final defeat of ISIS in Iraq," Prime Minister Haider al-Abadi said on Wednesday. Over the border in neighboring Syria, pro-government forces and US-backed Kurdish-led forces are conducting similar operations to clear ISIS militants from the countryside north of the Euphrates valley after ousting them from all urban areas.