Since December 2016, UNMISS has been led by the Secretary-General's Special Representative, South African lawyer and diplomat Nicholas Haysom.

[2] As of March 2021[update], it is composed of 14,222 military personnel, 1,446 police, and 2,228 civilian workers, as well as small contingents of experts, staff officers, and volunteers.

[22] Other contributors of troops are Australia,[23] Bangladesh, Belarus, Benin, Bolivia, Brazil, Cambodia, Canada, China, Colombia, Denmark, Dominican Republic, Egypt, El Salvador, Fiji, Germany, Ghana, Guatemala, Guinea, Indonesia, Japan, Jordan, Kenya, Kyrgyzstan, Mali, Mongolia, Namibia, Nepal, Netherlands, New Zealand, Nigeria, Norway, Oman, Papua New Guinea, Paraguay, Peru, Poland, Republic of Korea, Romania, Russian Federation, Rwanda, Senegal, Sri Lanka, Sweden, Switzerland, Timor-Leste, Togo, Uganda, Ukraine, United Kingdom, United Republic of Tanzania, United States, Vietnam, Yemen, Zambia and Zimbabwe.

[24] Police have been contributed by Algeria, Argentina, Bangladesh, Bosnia and Herzegovina, Brazil, Canada, China, El Salvador, Ethiopia, Fiji, Finland, Gabon, Gambia, Germany, Ghana, India, Kenya, Kyrgyzstan, Malaysia, Namibia, Nepal, Netherlands, Nigeria, Norway, Oman, Panama, Philippines, Portugal, Russian Federation, Rwanda, Samoa, Senegal, Sierra Leone, South Africa, Sri Lanka, Sweden, Switzerland, Thailand, Turkey, Uganda, Ukraine, United States, Zambia and Zimbabwe.

Johnson discussed the January 2012 Lou Nuer attacks in Jonglei State whereby the actions of UNMISS in deploying peacekeepers and alerting the South Sudanese government resulted in "thousands of civilian lives [being] saved", as well as progress in areas such as policing, justice and democracy.

[25] On 9 April, five Indian UNMISS troops and seven civilian UN employees (two UN staff and five contractors) were killed in a rebel ambush[26] in Jonglei while escorting a UN convoy between Pibor and Bor.

[34] Fighting that spread as a result of the 2013 South Sudanese coup d'état attempt led to the deaths of two Indian peacekeepers, while another soldier was wounded in Akobo, Jonglei, on 19 December.

[36] The UN Secretary General expressed deep concern as UN staff received threats from the body guards of Senior government Information Minister that demanded armed access to UN Mission Camps where civilians are sheltering.

The members of the Security Council condemned in the strongest terms these acts and underscored that attacks on civilians and UN peacekeepers may constitute a war crime.

[47] UNMISS continued to struggle to cope with the large populations of internally displaced people living within the 'Protection of Civilians' (PoC) sites in 2015.

[48] Ban Ki-moon requested an independent investigation of the deployment be made following reports that on 11 July South Sudanese troops rampaged through the capital, killing and raping civilians and foreign aid workers.

Ban Ki-moon requested on 1 November that Lieutenant General Johnson Mogoa Kimani Ondieki, the Kenyan force commander, be replaced as soon as possible.

[49] The next day the Kenyan Ministry of Foreign Affairs accused the United Nations of using Ondieki as a scapegoat and announced that it would be withdrawing all of its forces from South Sudan.

[57] In December 2017, the mission closed down the first Protection of Civilian site (PoC) in Melut town after IDPs voluntarily requested to return home.

[64] To prevent a new civil war in South Sudan, according to Fearon and Laitin's neo-trusteeship approach, a continuous international monitoring and support system might be required.