VIRGINIA TRIOLI: NATO has expressed grave concern about Russia's decision to suspend its membership of a treaty that regulates the deployment of conventional weapons in Europe. Russia's decision is in response to US plans to station anti-missile bases in Eastern Europe.

The Kremlin says the US is upsetting Europe's security balance. Michael Edwards has this report.

MICHAEL EDWARDS: Russia reverted to Cold War rhetoric.

SERGEI LAVROV, RUSSIAN FOREIGN MINISTER (Translation): We are concerned by the fact that NATO military infrastructure is creeping up to our border.

MICHAEL EDWARDS: Moscow claims that Washington's proposed anti-missile network, part of which will be based in Eastern Europe, is squarely aimed at Russia's nuclear arsenal. In protest, the Kremlin used a meeting of NATO foreign ministers to announce it had suspended its involvement with the Conventional Forces Treaty in Europe.

SERGEI LAVROV (Translation): Today, after analysis of the military treaty and considering Russia has been keeping its commitments, our president in his speech to Parliament, suggested how to change things further and so announced a moratorium on the treaty. And if that does not lead to radical changes, we will withdraw from the treaty.

MICHAEL EDWARDS: The treaty was signed shortly after the end of the Cold War. It regulates the level of conventional weapons allowed in Europe. Vladimir Putin had foreshadowed the move in his final state of the nation speech to the Russian Parliament before he steps down next year. President Putin also used that speech to take a broad swipe at US foreign policy.

The US says the missile shield is directed towards a perceived threat from rogue states such as North Korea and Iran, and not Russia. Secretary of State Condoleezza Rice says Moscow should respect the treaty.

CONDOLEEZZA RICE, US SECRETARY OF STATE: Of course these are treaty obligations and everyone is expected to live up to treaty obligations.

MICHAEL EDWARDS: NATO members expressed dismay at the move, but its secretary-general remains optimistic a compromise can be found.

JAAP DE HOOP SCHEFFER, NATO SECRETARY-GENERAL: Sergei Lavrov confirmed President Putin's statement made this morning that Russia is suspending, he used the word moratorium, its adherence to the adopted CFE treaty. I can tell you that that message was met by concern, grave concern, disappointment and regret.

MICHAEL EDWARDS: Both sides are wary of an unnecessary return to the corrosive suspicions of the Cold War.

Michael Edwards, Lateline.