In making the announcement, UNSMIL spokesman Samir Ghattas said the decision had been under study for months and not linked to any specific threat.
Ghattas did not say how many people work for the organisation or exactly how many were affected by the reduction.
He said UNSMILs work would "definitely be affected" but that the agency "will do our best... to continue our mission."
UNSMIL was created by the Security Council in 2011 to help Libyas
transitional authorities following the uprising that ousted and killed long-time dictator Moamer Kadhafi.
Its mission includes help to ensure the transition to democracy, promote the rule of law and monitor and protect human rights and control unsecured arms and counter their proliferation.
Libya has been awash with weapons since the end of the uprising against Kadhafi and has been gripped by increasing lawlessness.
(Uu.G003)
Editor: Priyambodo RH
Copyright © ANTARA 2014
