This illegal trade is extremely worrying in the context of peace operations, the official alerted the UN body in charge of ensuring international security.
Illicit flows of small arms and light weapons, she said, can worsen or sustain the dynamics of the conflict and render arms embargoes ineffective.
In addition, they endanger peacekeepers, humanitarian workers and local population, she stressed.
The illegal trade in small arms can complicate the gains made in peace accords around the world, she stressed.
Nakamitsu therefore encouraged members of the Security Council to integrate arms and ammunition management considerations into their conflict prevention efforts.