A United Nations Mission in South Sudan (UNMISS) peacekeeping soldier stands guard as children walk by during a patrol close to the town of Bentiu in Rubkona county, northern South Sudan, February 11, 2017. [Photo/Agencies]

"We reiterate that the government of Sudan will pursue the perpetrators until they are arrested and brought to justice," Sudan's Foreign Ministry said in a statement.

The ministry strongly condemned the killing of the UNAMID peacekeeper, expressing condolences to the victim's family and the government and people of Nigeria.

In a statement by UNAMID on Friday, the United Nations Security Council (UNSC) urged the Sudanese government to swiftly conduct a full investigation into the attack and bring the killers to justice.

Attacks targeting peacekeepers "constitute war crimes under international law," UNSC said.

On Thursday, UNAMID announced that one of its peacekeepers, a Nigerian, was killed by an unidentified group in a carjacking incident in Nyala, South Darfur State.

UNAMID was deployed in Darfur in 2008, with about 24,000 personnel, to keep peace in the region which has been suffering from a civil war since 2003.

Since its deployment, peacekeepers in the mission have experienced several attacks by unidentified groups, with more than 53 of them killed.

Since 2014, the Sudanese government has been demanding the exit of UNAMID from Darfur, citing improvement of security situations in the region, but its negotiations with the UN and AU are still underway.