Russia suspends arms control pact
BBC wrote:
Mr Putin signed a decree citing "exceptional circumstances" affecting security as the reason for the move.
Russia has been angered by US plans to base parts of a missile defence system in Poland and the Czech Republic.
The 1990 Conventional Forces in Europe Treaty (CFE) limits the number of heavy weapons deployed between the Atlantic Ocean and the Urals mountains.
The suspension is not a full-scale withdrawal - but it means that Russia will no longer permit inspections or exchange data on its deployments.
The allies consider this treaty to be an important cornerstone of European security," James Appathurai said.
He added that the move was "a disappointing step in the wrong direction".
Russia's suspension of its application of the treaty is yet another sign of a worsening relationship between the US and Russia.