A confidential report by UN experts, seen by the Reuters news agency, reported that several officers in the Democratic Republic of Congo said North Korea had supplied troops and police with pistols.
They also said North Korea had sent 30 instructors to provide training for the presidential guard and special forces.
A UN arms embargo prevents North Korea from importing or exporting weapons and training.
An arms embargo on DR Congo requires states to notify the UN Security Council sanctions committee of any arms sales or training.
The experts said they found that several Congolese army officers, as well as several police deployed abroad in a UN mission, appeared to have North Korean pistols.