US accuses Russia of violating nuclear weapons treaty after Putin boasts of 'unstoppable' missile

The US has accused Russia of breaking its treaty obligations after President Vladimir Putin announced a new array of “invincible” nuclear weapons. The US military stands ready to protect the nation, spokeswomen for the State Department and Pentagon asserted as they faced questions about Mr Putin’s declaration that “no anti-missile system – even in the future – has a hope of” stopping Russia’s new nuclear weapons. State Department spokeswoman Heather Nauert said Mr Putin confirmed what the US government has long known – that Russia has been developing destabilizing weapons systems for more than a decade, violating its obligations under the Intermediate-Range Nuclear Forces (INF) Treaty.