The African country's conflict has brought the total number of child recruitment to over 17,000.
Gharagozloo-Pakkala, in a statement, said the conflict has brought the total number of child recruitment to over 17,000 since a military conflict erupted between President Salva Kiir and his former deputy in late 2013.
“Since November, the UN has documented no fewer than 50 children abducted and recruited in the northern Greater Upper Nile region alone.
“The army and the rebels, as well as their allies, have been accused of recruiting children as fighters.
“Now, as the fighting intensifies and in spite of repeated pledges by all to end child recruitment, children are once again being targeted,” Gharagozloo-Pakkala said.
According to UNICEF, nearly 2,000 children have, meanwhile, been released by armed forces and armed groups in 2015 and this year.
Children are also suffering other kinds of abuses, the UN body said.
Since 2013, UNICEF and its partners have documented 2,342 cases of children being killed or maimed, with 1,130 children sexually assaulted.
They have also recorded 303 incidents of attacks on, or military use of, schools or hospitals.
“With fighting hampering farming and inflation soaring to at least 500 per cent over the past year, malnutrition among children has reached emergency levels in most parts of the country,” UNICEF said.
Kiir and his deputy, Riek Machar, formed a unity government in April, but fighting started again in July and drove the rebel leader into exile.
He is currently in South Africa.
The News Agency of Nigeria (NAN) reports that the conflict has left tens of thousands dead and displaced 3 million people.