"Those who are taking this step [supplying lethal weapons] are not interested in peace in Ukraine," Meshkov told RIA Novosti.
The Deputy Foreign Minister noted that if Western countries supplied Ukraine with lethal weapons, it would be a breach of their obligations made within the framework of the Organization for Security and Co-operation in Europe and the Arms Trade Treaty.
Western nations have been at odds over the issue of delivering lethal aid to Ukraine, with the split becoming even more apparent over the past few days.
Last week, a group of US senators called on President Barack Obama to provide lethal assistance to Ukraine. Russia has voiced concern that the proposed US arms deliveries to Kiev could lead to an increase in violence in conflict-stricken Ukraine.