The "curfew will be imposed in all provinces of Iraq on November 20 and 21 to conduct a population census", Prime Minister Mohamed Shia al-Sudani said in a statement.

Ravaged by decades of conflict and violence, Iraq has postponed a census several times, most notably in 2010 because of tensions between communities over disputed territories.

The last general census was held in 1997 in 15 Iraqi provinces -- excluding the three northern provinces that made up the autonomous Kurdistan Region.

Iraq has regained some semblance of stability in recent years, despite sporadic violence and political turmoil.

Current estimates put today's population at around 43 million.

The authorities have partnered with the United Nations Population Fund (UNFPA) for the upcoming census.

The initiative "plays a crucial role in equipping Iraq with accurate demographic information, facilitating effective policymaking, and promoting inclusive growth," the agency has said.

In the past, Iraq held a census every 10 years. A count could not be organised in 2007, when the country was embroiled in sectarian violence.