It comes after Iraqi forces, backed by US-led airstrikes, drove Islamic State (IS) militants out of the centre of the city of Ramadi and seized the main government complex there.
Ramadi, the provincial capital of the western Anbar province, fell to IS in May, marking a major setback for Iraqi forces and the US-led campaign.
Ramadi and nearby Fallujah, which is controlled by IS, saw some of the heaviest fighting of the eight-year US intervention in Iraq.
Now Finance Minister Hoshiyar Zebari said the next planned offensive would be to recapture Mosul, the largest city under IS control.
Mosul was once home to most of Iraq's Christians but almost all had to flee when IS took over.
The militant group told believers to convert to Islam, pay a tax or they would be killed.
Mr Zebari said retaking the city would be "very challenging" and could take some time.
He said: "Mosul needs good planning, preparations, commitment from all the key players.
"It will not be an easy operation, for some time they have been strengthening themselves, but it's doable."
In February Premier revealed the Iraqi Army had started drawing up plans to capture Mosul.
Retired Major General Tim Cross told Premier the UK was helping the country's force get ready to strike Mosul.
If it's taken back from IS it would be seen as a major achievement in the fight against the group.
He said: "We need to make sure that when we go on the offensive, it's got to succeed."
