Some eight months after the UN Security Council approved the deployment of the Regional Protection Force (RPF) to South Sudan, the first of those troops have just trickled in amid bureaucratic hurdles by the government.

UN Secretary-General Antonio Guterres said in a monthly report on the status of the deployment and obstacles facing some 13,000 UN peacekeepers already on the ground that the situation in South Sudan has deteriorated at a rapid pace.

Guterres told the Security Council in a report seen by Reuters on Thursday that while it usually takes several months for the United Nations to get the troop contributions needed for the deployment of the UN troops, the world body has also had to contend with the South Sudanese government's red tape and unwillingness to cooperate.

"It is indeed unfortunate that the first troops associated with the RPF have only begun to arrive eight months after they were initially mandated by the Security Council," Guterres wrote, adding that as of May 15 there were 31 members of the Bangladesh Construction Engineering Company on the ground.

Guterres pointed out that UNMISS continued to be obstructed and restricted in South Sudan, adding that humanitarian aid deliveries were being obstructed.