Looking to help stave off advances by the Islamic State group in Iraq, the U.S. plans to begin buying $24.1 million worth of arms for Sunni Muslim tribesman. The weapons would include AK-47s, rocket-propelled grenades and mortar rounds, according to a Defense Department document sent to Congress cited by Reuters.

Overall, the Pentagon requested $1.6 billion to train and arm Iraqi and Kurdish forces in the region to battle the Islamic State group. In Ramadi, the capital of the Anbar province, the Iraqi government is embroiled in a battle with Islamic State forces for control of the region.

The Pentagon document underscored the importance of arming the tribesmen and insisted that such a strategy was necessary to quell further conquests in the area by the militant group.

“Not arming tribal fighters will continue to leave anti-ISIL tribes reluctant to actively counter ISIL,” the Pentagon said in the document, noting that the Islamic State, formerly known as either ISIL or ISIS, has seized control of large parts of Iraq and Syria and is gaining territory in Anbar despite three months of U.S.-led airstrikes.

Iraqi Prime Minister Haider al-Abadi has called for more aerial support and weapons for government troops and Sunni tribesmen clashing with the Islamic State group in the area, the Associated Press reported. A curfew has been imposed in Ramadi after fighting escalated between Iraqi and militant forces. The Islamic State group has already taken multiple towns and cities in the Anbar province, including Fallujah.

Al-Abadi called for the additional support meeting with delegates of the Anbar Provincial Council Saturday, AP reported.