South Sudan's former deputy defense minister and member of the former political detainees group, Majak D'Agoot, Sunday said he had been denied a visa by Sudan’s Embassy in Nairobi to attend a meeting on issues of the Horn of Africa in Khartoum.

A three-day meeting organized by the African Union (AU), the East Africa bloc IGAD and the Sudanese government kicked off on Sunday in Khartoum. The meeting is set to discuss issues of peace, security, stability, cooperation and development in the Horn of Africa region.

Majak told Radio Tamazuj that he had received an invitation letter from the African Union to attend the meeting to discuss challenges facing the Horn of Africa region.

Sudan’s Embassy in Nairobi confirmed that it had denied a visa to Majak. However, the embassy didn’t cite any clear reasons.

The former detainees group’s spokesman Kosti Manibe Ngai said that Majak was invited as a security expert in the Horn of Africa and not as a member of the former political detainees.

Majak had served as deputy head of National Security and Intelligence Services before South Sudan’s independence from Sudan in 2011.