South Sudan said Monday that it "deeply regrets" dozens of cases of harassment and threats against United Nations staff by its army and police.
The government of the world's youngest country has faced pressure from the UN Security Council and the United States over beatings of UN staff and other incidents in recent months.
UN leader Ban Ki-moon complained in a report last week of 67 cases of "harassment, threats, physical assault, arrest and detention of United Nations staff" and seizure of UN vehicles between May 7 and November 5.
In one case on October 19, a female UN staff member was "severely beaten" in the capital, Juba, and then detained following "a traffic encounter with a military pickup carrying armed uniformed men," said Ban's report.
Diplomats said the case involved a convoy of South Sudan's president, Salva Kiir.
"We deeply regret both the character and the number of incidents that have occurred," South Sudan's UN Ambassador Francis Deng told a Security Council meeting on his country.
"The government is seriously committed to ending these violations. Orders have indeed been given toward that end and to hold those responsible accountable," Deng said, adding that the country's young army needed more training and "sensitization."
The United States approached South Sudan's UN mission last week and China made a similar complaint on behalf of the Security Council.
UN representative to South Sudan, Hilde Johnson, said she had warned the South Sudan cabinet over the incidents at a recent meeting.
"I expressed grave concern over this worrying trend," Johnson said. She added that President Kiir had "expressed dismay" over the harassment of UN and diplomatic staff.
She said the government had issued written orders to the Sudan People's Liberation Army and the police last week, which included a warning that off-duty security personnel should not wear uniforms nor carry guns.
The UN mission, UNMISS, has 7,600 troops and police in South Sudan, which broke away from Sudan after a two-decade-long civil war in which two million people died.
There have been a series of incidents involving the UN since South Sudan became independent in July 2011.
The government expelled a UN human rights investigator in October 2012 accusing her of writing "false" reports about army abuses.
Two months later, South Sudan's army shot down an UNMISS helicopter killing all four Russian crew on board.