The United Nations received 138 allegations of sexual exploitation and abuse last year and nearly half were against UN peacekeeping missions, a report said on Tuesday.
Secretary-General Antonio Guterres said in the report that the 62 allegations against personnel in 10 peacekeeping missions and one political mission were a drop from the 104 claims reported in 2016.
There was a sharp decrease in allegations recorded for the MINUSCA mission in the Central African Republic: 19 last year compared to 52 in 2016.
Gabon last week announced that it was withdrawing its troops from MINUSCA following cases of sex abuse and other problems.
MINUSCA has been hit by a string of sex abuse allegations against peacekeepers that led to the firing of the mission commander in 2015 and the repatriation of contingents which faced repeated accusations.
Guterres has vowed to toughen the UN response to allegations of misbehavior by peacekeepers and UN personnel whose mission is to protect vulnerable civilians in conflict zones.
"No individual serving under the United Nations flag should be associated with sexual exploitation and abuse," Guterres said in the report.
"Combating this scourge continues to be one of my key priorities for 2018, as is assisting and empowering those who have been scarred by these egregious acts."
There are more than 90,000 military personnel assigned to UN peacekeeping operations.