In February 1992, the Organisation for Security and Co-operation in Europe (OSCE) requested that all OSCE participating states should introduce an embargo on 'all deliveries of weapons and munitions to forces engaged in combat in the Nagorno-Karabakh area'. 

Source: Committee of Senior Officials, Journal No. 2, Annex 1, Seventh Committee on Senior Officials meeting, Prague, 27-28 February 1992

This embargo is still in force.