Matteo Salvini, who heads Italy's Northern League party, called NATO’s decision to establish additional command centers in six European countries madness.
"NATO deploys forces on the border with Russia. Another madness after economic sanctions: war is not a game," he tweeted.
NATO's growing presence in Eastern Europe has been the subject of geopolitical tensions, with Russia having expressed growing concern over the buildup of NATO forces along its western border.
NATO, which has accused Russia of being involved in the Ukrainian crisis, claims that the expansion is aimed at protecting its member-states and allies.