Pope Francis appealed to South Sudan leaders to "lower the tension in the country" as Catholic bishops in Sudan and South Sudan expressed alarm at the escalating violence in the world's youngest nation and warned of a catastrophe if full-scale war returns.

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.

South Sudan has reversed its decision to deny entry to a man it said was a Congolese national deported by the United States after Washington imposed a blanket visa ban on South Sudanese citizens.