NATO has expressed grave concern at Russian President Vladimir Putin's decision to freeze Moscow's commitments under a European arms control pact.Russia withdrew from Europe's main arms control treaty in an angry response to American plans to deploy a missile defence system in two former Warsaw Pact countries.Vladimir Putin accused the United States of a plot to build up its military forces on Russia's western borders and announced a suspension of Moscow's participation in the Conventional Forces in Europe (CFE) Treaty.The Russian's move followed the Pentagon's announcement that it planned to deploy ten interceptor missiles in Poland and a radar system in the Czech Republic.NATO Secretary General Jaap de Hoop Scheffer said Russian Foreign Minister Sergei Lavrov confirmed Putin's announcement suspending Russia's implementation of the CFE pact to NATO ministers at a meeting in Oslo."That message was met by concern, grave concern, disappointment and regret," de Hoop Scheffer told a news conference.He added: "The allies are of the opinion that the CFE is one of the cornerstones of European security".Minutes later, Lavrov defended the Russian move at a separate news conference."I think that we cannot be unconcerned by the fact that NATO military infrastructure is creeping up to our borders," he said.Lavrov said Russia had been complying with the treaty and it was time for NATO to show it was serious about it, warning: "Unless our partners do that we will withdraw from the treaty."American attempts to pacify the Kremlin by inviting Russia to inspect the proposed sites and cooperate in the project have have failed.US Secretary of State Condoleezza Rice described Russia's fears as "ludicrous."© Independent Television News Limited 2007. All rights reserved.