UNITED NATIONS (AP) — The U.N. Security Council voted unanimously Thursday to extend the mandate of the U.N. peacekeeping mission in South Sudan, welcoming “encouraging developments” toward peace and a reduction in political violence by the warring parties after six years of civil war.

The council demanded that all parties to the conflict immediately end all fighting in the country, engage in political talks and implement a permanent cease-fire called for in several agreements but never implemented.

It threatened sanctions “against those who take actions that undermine the peace, stability, and security of South Sudan.”

There were high hopes that South Sudan would have peace and stability after gaining its long-fought independence from neighboring Sudan in 2011. But the world’s youngest nation slid into ethnic violence in December 2013, when forces loyal to President Salva Kiir, a Dinka, started battling those loyal to Riek Machar, his former vice president who belongs to the Nuer people.

Numerous attempts at peace failed, including a deal that saw Machar return as vice president in 2016 — only to flee the country months later amid fresh fighting. The civil war has killed nearly 400,000 people and displaced millions.

Intense international pressure followed the most recent peace deal in 2018, and on Feb. 22 a coalition government led by Kiir, with Machar as his deputy, was formed.

The Security Council called the beginning of a national unity government “a significant step towards sustainable peace.” It welcomed “the spirit of compromise and political will demonstrated by the parties in order to create the conditions necessary to advance the peace process.”

The U.S.-sponsored resolution extends the mandate of the U.N. peacekeeping force until March 15, 2021, and maintains its overall force levels at a maximum of 17,000 troops and up to 2,101 international police personnel.

The peacekeeping mission’s main mission remains the protecting of civilians, delivering humanitarian aid, supporting the implementation of the 2018 peace agreement, and monitoring and investigating human rights abuses and violations of international humanitarian law.

The Security Council expressed “urgent concern” over the nearly 3.9 million people displaced within South Sudan and the country's humanitarian crisis, with an estimated 5.29 million people facing “severe food insecurity ... and 7.2 million in need of life-saving assistance.”

U.S. Mission senior adviser Michael Barkin told the council after the vote that this was the first time in many years that the force’s mandate was renewed “in the context of positive developments.”

“The United States reiterates its support for the decision by South Sudan’s leaders to form a new transitional government,” Barkin said. “We also recognize the hard work of implementing the peace agreement is just beginning, and we urge the transitional government to begin this reform process immediately.”

Germany’s deputy ambassador, Jurgen Schulz, encouraged implementation of “outstanding critical tasks” so South Sudan’s people “can finally profit from the benefits of durable peace.”

He said Germany was pleased the resolution includes a reference to the adverse effects of extreme weather on South Sudan, which saw a swarm of locusts last month, but disappointed a reference to the security implications of climate change was not included. Diplomats, speaking on condition of anonymity because consultations on the text were private, said the U.S. and Russia objected.