Iraq postponed its first full census in more than two decades until December on Sunday to avoid triggering open conflict between Arabs and Kurds locked in a row over a swathe of oil-rich land in the north.

The census is a keenly awaited event because it will answer questions key to the future of northern oilfields -- areas in Nineveh and Kirkuk disputed by Arabs and Kurds.

The US has warned against rushing into the count, previously slated for Oct. 24, at a time when Iraq is struggling to contain insurgent violence after years of sectarian war.

Environment Minister Nermeen Othman, who attended a cabinet meeting that took the census decision on Sunday, said the survey would now be held on December 5.

She said the government wanted to "reassure all sides the census is focused only on development issues and not politics".

Mehdi al-Alak, a deputy planning minister and head of the statistics office, said the government wanted to give Kirkuk and Nineveh more time to settle tensions before holding the sensitive count.

"They (Arabs) have some demands concerning the disputed areas," Alak, who attended the same meeting, told Reuters. He gave no details on what exactly was being discussed.

Iraq has been locked in months of political uncertainly after an inconclusive parliamentary election in March produced no outright winner.

The protracted disagreement has cast the Kurds in the role of kingmakers, with their lawmakers pressuring incumbent Prime Minister Nuri al-Maliki to meet their demands in exchange for Kurdish support in forming a new government.

Iraq had already postponed plans to hold a census when the country was at the peak of sectarian violence in 2007.

The survey is crucial because it will determine if Kurds are the biggest ethnic bloc in Kirkuk, a northern city lying on vast oil reserves, and can therefore claim it as its own.

If the census finds they are a greater percentage of the total population than previously believed, the constitution says the region must get a larger slice of the federal budget than its current 17 per cent, and retroactive payments.

There are also worries that the census could further fuel sectarian discord between Shi'ites, Sunnis and minority Kurds although the government has specifically decided to avoid asking Iraqis to say whether they are Shi'ite or Sunni.

The first complete census since 1987, it will seek answers to many other questions as well, such as how many widows, orphans and disabled people there are after decades of war. – Reuters