Johannesburg - The United States Treasury's office of foreign assets control has sanctioned South Sudan's first vice president Taban Deng Gai for his role in serious human rights abuses.
Washington has condemned the delays in implementing a peace deal signed in September 2018 between the South Sudan government and the main opposition to end a five-year civil war.
A statement from the state department said President Donald Trump's government had designated Deng under an executive order which implements the Global Magnitsky Human Rights Accountability Act.
"This decision underscores the US government’s continuing commitment to promote and protect human rights globally and reflects our determination to promote accountability of all those who seek to undermine the South Sudanese peace process," it said.
Deng was sanctioned for his involvement in the disappearance and reported deaths of two human rights activists in 2017.
The state department said he had acted on South Sudan President Salva Kiir’s behalf "to divide and sow distrust, extend the conflict in South Sudan, and impede the reconciliation and peace process".
"Disappearances and extrajudicial killings of political opposition and civil society actors whose views differ with the ruling regime are actions designed to silence dissent and enforce the political status quo," it said.
"Such human rights violations and abuses curtail the political space needed for the full implementation of a durable peace in South Sudan."