The Pentagon said that the Takfiri group, ISIL, has lost control of "25 to 30" percent of the territory it seized last June.

The Pentagon said that the Takfiri group, ISIL, has lost control of "25 to 30" percent of the territory it seized last June.

Following months of military operation by the Iraqi army, backed by the popular mobilization forces, the ISIL grip on parts of the country is fading, the Pentagon said.

"ISIL is now being slowly pushed back," said Pentagon spokesman Colonel Steve Warren.

"Iraqi security forces and coalition airpower have unquestionably inflicted some damage on ISIL,” Warren added.

In addition to the army operation, an air campaign is also striking the terrorists across Iraq and sometimes in Syria. Since August, the US-led coalition aircraft have conducted airstrikes on 3,244 ISIL targets, 1,879 in Iraq and 1,365 in Syria.

The lost territory amounts to some 13,000 to 17,000 square kilometers (5,000 to 6,500 square miles), Warren said.

US President Barack Obama meets Tuesday at the White House with Iraqi Prime Minister Haider al-Abadi.