A joint report sent to the UN Security Council last month recommends that the ceiling set for military troops be cut.
A joint report sent to the UN Security Council last month recommends that the ceiling set for military troops be cut by 44 percent and the maximum number of police reduced by 30 percent in the UNAMID force.
The Security Council is expected to discuss the proposals next week.
The cuts to the 17,000-strong UNAMID force would result in major savings to the UN peacekeeping budget at a time when the United States is seeking to reduce its financial contribution to the blue helmets.
UNAMID has a budget of $1.04 billion per year, making it one of the UN's costliest missions along with the UN force in the Democratic Republic of Congo.
Under the proposal outlined in a strategic review of the UNAMID force, the troop level would drop to 8,735 and the police strength would stand at 2,360.
The drawdown would be carried out in two six-month phases.
The report cited an "improvement in the security situation" as a result of the Khartoum government's offensive against rebel groups in Darfur, which are now confined to parts of western Jebel Marra.
Darfur has been engulfed in conflict since 2003, when ethnic minority insurgents mounted a rebellion against President Omar al-Bashir, complaining that his Arab-dominated government was marginalizing the region.
Bashir launched a brutal counter-insurgency, and the United Nations says that at least 300,000 people have been killed in the conflict and another 2.5 million have been forced to flee their homes.
The UN-AU joint mission "should adjust to the new realities in Darfur and the Sudan," said the report from UN Secretary-General Antonio Guterres and African Commission chair Moussa Faki Mahamat.
The peacekeepers would withdraw from several sectors in Darfur and concentrate the mission's main military effort on Jebel Marra, said the report dated May 18.