An outbreak of violence in South Sudan overshadowed the nation's fifth anniversary of independence this weekend, as more than 200 people were reportedly killed in fighting between forces aligned with President Salva Kiir and rival Vice President Riek Machar.
The Associated Press obtained a copy of the order.
A ceasefire appears to be holding in South Sudan's capital, Juba, after four days of heavy fighting between rival forces left hundreds dead.
President Salva Kiir declared a halt in fighting that began Thursday night and has raised fears of a return to civil war that could draw in even more of the East African country's ethnic groups. At least two United Nations peacekeepers were killed and several wounded.
The UN mission in South Sudan should also be strengthened with attack helicopters, Ban said. The country has just emerged from a two-year civil war.
"(Our staff) said they've tried to leave their neighbourhood because they don't feel safe and they are taking cover under their beds with their children", Concern Worldwide's country director Feargal O'Connell said via Skype from Juba.
"For peace to stand a chance, the UN Security Council must ensure that all countries halt any further flow of weapons into South Sudan by immediately imposing a comprehensive arms embargo".
South Sudan became independent from Sudan in 2011 but its short history has been marred by years of civil war.
"[It's a] few men with lots of power who are struggling to control the process where money comes from", said David Majok, president of the South Sudanese Community Association in Ottawa.
In a statement the UN Security Council said the recent fighting showed a "lack of serious commitment" to peace on the part of Kiir, Machar and their supporters.
Both Kiir and Machar have ordered a ceasefire.
"All the regular forces that were deployed because of whatever, they need to go back to their respective units, any soldier or any member of the regular forces that will be found loitering about with his rifle without reporting to his unit will be arrested and immediate action will be taken", Makuei cited Kiir as saying.
Numerous thousands displaced by the renewed fighting in Juba are seeking shelter at the two U.N. bases, a World Food Program compound and other areas, said U.N. Office for the Coordination of Humanitarian Affairs spokeswoman Matilda Moyo.
In this photo taken late Friday, July 8, 2016 and released by the United Nations Mission in South Sudan (UNMISS), villagers looking for safety on the UN base during the fighting near perimeter of the UN base and compound in the capital Juba, South Sudan.