President George W. Bush today announced the withdrawal of the US from the 1972 ABM Treaty.
He said his decision to pull out "will not in any way undermine" the new Russo-US relationship or Russian security.
Mr Bush said Russian President Mr Vladimir Putin agrees "that my decision to withdraw from the treaty will not in any way undermine our new relationship or Russian security".
Russian politicians condemned Washington's departure from the ABM treaty, but few expect Mr Putin to make a drama out of a crisis from which he should emerge unscathed.
Russia says the demise of the pact, the bedrock of three decades of disarmament, could unravel more than 30 other accords, undermining international security at a time when the Afghan crisis puts strategic stability at a premium.
"It's worse than a crime, it's an error," said Mr Vladimir Lukin, a former Washington ambassador and leading light in the liberal Yabloko Party.
AFP