The UN Security Council has changed the peacekeeping mission in South Sudan to focus on protecting civilians, instead of nation building. Severe ethnic violence broke out last year, killing thousands.
The resolution, passed unanimously by the 15-member council on Tuesday, amends the UN peacekeeping mission in South Sudan to concentrate on the protection of civilians.
The focus changes from the previous mandate of peace-building and fostering political transition in the country.
The resolution "emphasizes that protection of civilians...must be given priority in decisions about the use of available capacity and resources within the mission."
A power struggle between South Sudanese president Salva Kiir and his former deputy Riek Machar, turned deadly last year. The violence has been fueled by ethnic divisions between Kiir's Dinka people and the Nuer of Machar.
The conflict has seen seen thousands die and a million people flee their homes.
The UN Security Council authorized UN troops to "use all necessary means" to protect civilians, monitor and investigate human rights abuses, assist in delivering humanitarian aid and support a deal to end hostilities.
An initial ceasefire was signed in January but fighting continued in South Sudan, which became independent from Sudan in 2011. A second agreement was signed in early May between Kiir and Machar in Ethiopia, and has led to a tense standoff.
Peacekeepers working in the current South Sudan mission are protecting around 80,000 civilians at UN bases.
A report released earlier this month alleges both sides had likely committed crimes against humanity, including rape and mass killings.