The deputy chief of staff of the SPLA-IO group for administration has returned to the capital Juba as part of the revitalized peace deal.
The arrival of the top SPLA-IO general is a major symbolic step towards confidence-building among military commanders in the country.
General James Koang Chuol arrived in Juba this week more than two years after fighting in the capital.
The military told Radio Tamazuj Wednesday that a delegation of high-level SPLA-IO military officials led by General James Koang is currently in Juba to participate in meetings of the security-related committees set up as part of the peace deal.
Army spokesman Lul Ruai Koang said the delegation, which comprises members of the armed opposition on various security-related mechanisms, came to take part in meetings and workshops.
The UN peacekeeping chief Jean-Pierre Lacroix told the UN Security Council on Tuesday that the security-related committees in South Sudan have made little visible progress.
Under the peace deal signed in September, a new unity government will be formed in May 2019.