In an advisory to US businesses, the Departments of State, Commerce and Labor together told them of “the growing reputational, financial and legal risks” to transactions linked to South Sudan’s government or companies controlled by officials’ families.

It called on US businesses to do “due diligence on corruption and human rights issues” and to avoid any dealings that involve South Sudanese officials who are under sanctions.

The advisory faulted the transitional government for its “failure to adhere to its own laws” including on transparency over oil revenue.

Business dealings could “adversely impact US businesses, individuals, other persons and their operations in South Sudan and the region,” it said.

The United States helped spearhead diplomacy for the 2011 independence of majority-Christian South Sudan following two decades of war with Sudan’s majority-Muslim and Arab government in Khartoum.

The new country quickly descended into civil war that killed hundreds of thousands of people, with the United States and other Western powers accusing President Salva Kiir and his rival-turned-deputy Riek Machar of dragging out implementation of a 2018 deal so they could cling to power.

The United States has halted support for the peace process but maintained humanitarian aid to South Sudan, one of the world’s poorest countries.