The Islamic State of Iraq and the Levant, a group with ties to al-Qaida, took control of Fallujah in Anbar province last week. Parts of Ramadi, the provincial capital, are also in the hands of al-Qaida fighters.
Maliki issued a statement Monday calling on residents and area tribes to take action against the terrorist group, al-Arabiya reported.
"The people of Fallujah and its tribes [are called on] to expel the terrorists [so] their areas are not subjected to the danger of armed clashes," the prime minister said.
Parts of Anbar province were at risk of falling into terrorist hands at the height of the insurgency that followed the U.S.-led invasion in 2003.
U.S. Secretary of State John Kerry said during a Sunday news conference there were no plans to put U.S. boots on the ground in Iraq.
"This is their fight," he said.
Maliki said Iraqi security forces were called on to avoid striking residential areas in Fallujah.