South Sudan's Ministry of Foreign Affairs claims they made a mistake when they said in an official statement to the United Nations that Luka Biong who hails from the disputed Abyei area is not a South Sudanese citizen.

The ministry had written in a response to a UN human rights report that Luka Biong, the director of the Centre for Peace and Development Studies at the University of Juba, was actually a Sudanese citizen.

The ministry was responding to the UN report which among other alleged restrictions on free thought and expression cited the dismissal of Dr Biong from his position after he organized a symposium to debate President Salva Kiir's order to create 28 states.

But the ministry has since tried to backtrack its statement which was signed by Foreign Affairs Minister Barnaba Marial Benjamin.

"The statement was issued by the government of South Sudan not the ministry of Foreign Affairs," said ministry spokesperson Mawein Makol. "There was a mistake in the statement and the minister of Foreign Affairs signed the cover of the statement without realizing the mistake but it has been corrected now."

Mawein insisted that all sons of Abyei are South Sudanese citizens.

Abyei is a contested region between Sudan and South Sudan. The region is claimed by the Arab Misseriya tribe and the Ngok Dinka tribe. The Ngok Dinka voted to join South Sudan a few years ago but neither Khartoum nor Juba recognized the results of the referendum.