Iraq seeks Trump support as Mosul battle advances
The operation has free around one-third of the area and resulted in the death of over 1,000 IS militants and the imprisonment of 650 others, Reuters reported Ibrahim al-Jaafari as saying.
Jaafari praised US backing of the operation, adding that the cohesion of Iraqi forces with the US-led coalition was better than expected.
"Those are very good signs for the positive results of the operations. It's going better than we expected," al-Jaafari said.
"Of course the fight must continue. But it's clear that the cohesion of the forces and the coalition played a significant role up to now," he added.
Although it is unclear how long the battle will last, Jaafari called for continued US support under President-elect Donald Trump, adding that US-backing remains essential to the operation.
"We don't have agreements with individual administrations. We have agreements with countries," he said.
"These strategies don't change with the presidents. Agreements are signed and then they are binding for all involved."
A US-led coalition is carrying out air and artillery strikes in support of Iraqi forces in Mosul.
The coalition said it has targeted the militants with thousands of bombs, missiles, rockets and shells.
In the closing stages of his presidential campaign, Trump had repeatedly mocked the ongoing Mosul operation.
Trump said that President Barack Obama's generals had flagged up the siege four months in advance, giving the IS a warning on the assault.
"What a group of losers we have," Trump said, "They should have kept their mouths shut."