Russia confronted the US in recent weeks with the possibility of withdrawing from a key nuclear and conventional missile disarmament treaty that formed the bedrock of arms reduction efforts during the cold war.

At a meeting in Washington in January, Sergei Ivanov, the Russian defence minister, asked Donald Rumsfeld, his US counterpart, how the Bush administration would respond if Russia quit the Intermediate-Range Nuclear Forces treaty (INF), the Pentagon said. In a blow to Russian military hawks, a delegation from the Foreign Ministry later travelled to Washington to withdraw the proposal, the Russian source said.