The head of the UN mission to the Democratic Republic of Congo is to leave his post.
Thousands of people have fled ethnic violence in Ituri
Top envoy William Lacy Swing will be replaced by a new special representative later in the year.
The UN mission in DR Congo has faced criticism after allegations that UN peacekeepers sexually exploited refugees in their care.
UN spokesman Fred Eckhard said Mr Swing would remain in the job for the time being to allow for a smooth transition.
Violence has flared in the turbulent north-eastern Ituri region of DR Congo, where the UN has one of its largest missions, with more than 13,000 troops.
In late February, nine Bangladeshi peacekeepers died when they were ambushed whilst on patrol in the area and, on Tuesday, 50 militiamen were killed during a UN operation against the militia in the same area.
"The secretary general noted that Mr Swing evidently had his hands full across all these fronts and would need to show strong leadership in all these areas," Mr Eckhard said.
"They concluded that with his plate so full, this was not the moment for a sudden change of special representative," he added.
Last month, a UN team investigated 72 allegations of abuse by UN peacekeepers and civilian staff.
According to its report, published in January, 26 of these claims were substantiated and included cases of girls as young as 12 being given small sums of money or food items in exchange for sex with soldiers based around the north-eastern town of Bunia.
In response, the UN introduced a strict non-fraternisation policy, banning its peacekeepers from having sex with local people.
Six Moroccan soldiers were also arrested following the investigation.