The United States once cheered the creation of South Sudan as an independent nation. Now the Trump administration has abruptly revoked the visas of all South Sudanese, saying the country’s government has failed to accept the return of its citizens “in a timely manner.”

The decision means South Sudanese could be returned to a nation again on the brink of civil war or unable to seek the U.S. as a haven.

There was no immediate response from South Sudan’s government, which has struggled since independence from Sudan in 2011 to deliver some of the basic services of a state. Years of conflict have left the country of more than 11 million people heavily reliant on aid that has been hit hard by another Trump administration decision — sweeping cuts in foreign assistance.

Here’s a look at South Sudan, whose people had been granted temporary protected status by the U.S. because of insecurity at home. That status expires May 3.

A deadly divide

The euphoria of independence turned to civil war two years later, when rival factions backing President Salva Kiir and deputy Riek Machar opened fire on each other in South Sudan’s capital, Juba, in 2013.

Tensions between the two men have been at the heart of the country’s insecurity, so much so that Pope Francis once took the extraordinary step of kneeling to kiss their feet in one of his pleas for lasting peace.

Five years of civil war killed hundreds of thousands of people. A peace deal reached in 2018 has been fragile and not fully implemented, to the frustration of the U.S. and other international backers. Notably, South Sudan still hasn’t held a long-delayed presidential election, and Kiir remains in power.

His rivalry with Machar, compounded by ethnic divisions, has simmered through multiple attempts to return Machar as a vice president. Machar has long regarded himself as destined for the presidency, citing a prophecy years ago by a seer from his ethnic group.

Late last month, the threat of war returned. Machar was arrested and his allies in the government and the military were detained following a major escalation: A militia from Machar’s ethnic group had seized an army garrison upcountry. The government responded with airstrikes. Dozens of people were killed. A United Nations helicopter was attacked.

Following the arrest, Machar’s opposition political party announced South Sudan’s peace deal is effectively over.

“Let’s not mince words: What we are seeing is darkly reminiscent of the 2013 and 2016 civil wars, which killed 400,000 people,” U.N. Secretary-General António Guterres warned days ago.

Some Western countries have closed their embassies there while others, including the U.S., have reduced diplomatic staff.

A country in disarray

South Sudan’s government has long relied on the country’s oil production. But little of that money has reached the people, in part because of official corruption. Civil servants at times go months without being paid.

Conflict in neighboring Sudan has affected landlocked South Sudan’s exports of oil. Refugees spilling over from Sudan have added to instability at home.

Climate shocks including flooding have caused mass displacement and closed schools. South Sudan’s health and education systems were already among the weakest in the world. Aid organizations have run or supported many. Now that support network has been hit by sweeping cuts in U.S. aid.

U.S. Secretary of State Marco Rubio’s announcement Saturday evening revoking visas for all South Sudanese passport holders, effective immediately, is in sharp contrast to Washington’s past warm embrace as South Sudan’s rebel leaders — including Kiir and Machar — fought for independence.

Educational and other opportunities for South Sudanese have been available in the U.S. for years. On Saturday, hours after Rubio’s announcement, a freshman from South Sudan was in Duke’s starting lineup at the men’s NCAA basketball tournament Final Four — 7-foot-2 center Khaman Maluach. Duke spokesman Frank Tramble told the Associated Press the university was aware of the announcement and was “working expeditiously to understand any implications for Duke students.”

It was not immediately clear how many South Sudanese hold U.S. visas or how American authorities will follow up. Deputy Secretary of State Christopher Landau said on social media the dispute centers on one person, certified by the South Sudanese Embassy in Washington, that Juba has refused to accept. That person was not named.

No new visas will be issued, the U.S. said, and “we will be prepared to review these actions when South Sudan is in full cooperation.”

Anna writes for the Associated Press. AP sports writer Jim Vertuno in San Antonio contributed to this report.