Rubio noted the order has already complicated U.S. diplomacy with Libya, South Sudan and Djibouti and presents a serious threat to the president’s Article II authority to conduct foreign policy.

The U.S. State Department has a Level 4 travel advisory for South Sudan, warning Americans not to travel there due to "crime, kidnapping, and armed conflict." ...

How South Sudan is equipped to handle migrants arriving abruptly from the U.S. is yet to be seen. Associated Press journalist Florence Miettaux in Juba, South Sudan, contributed.