Abadi has been grappling with a political crisis since February and has been unable to rally the main blocs in parliament to back an anti-corruption plan that includes a cabinet reshuffle.
He ordered the offensive on Fallujah on May 22, after the political crisis degenerated into deadly street violence in and near to Baghdad's heavily fortified Green Zone, and a series of bombings, claimed by Daesh, hit parts of the city.
"I appeal (to the politicians) to freeze all differences until the land is freed," he said on state TV late Wednesday during a visit to the army's frontline near Fallujah, 50 kilometers (32 miles) west of Baghdad, AFP reported on Thursday.
"Daesh is the ultimate corruption and whoever prevents us from fighting Daesh is corrupt," he added, referring to the terrorist group.
Since the offensive on Fallujah began, there have been no attempts by demonstrators to storm the Green Zone, which houses the Iraqi parliament, government offices and embassies.
Protesters, including followers of cleric Moqtada al-Sadr, had previously stormed the Green Zone twice to press for reforms, on April 30 and May 20.
Abadi pledged last December that 2016 would be the year of "final victory" against the terrorists, predicting the capture of their de-facto capital Mosul in northern Iraq.
Fallujah is the second largest Iraqi city after Mosul to remain under Daesh control. It is the first Iraqi city that the group captured, in January 2014.