Russian President Vladimir Putin has said Russia was prepared to drop a nuclear weapons agreement treaty with the US.<br />''<span style="color: #222222;"><br />''Talking to media at Saint Petersburg, Putin warned global catastrophe if Washington keeps dismantling a global arms control regime.<br />''<br />'' He said Washington showed no genuine interest in conducting talks on extending the New START treaty which caps the number of nuclear warheads well below Cold War limits. <br />''<br />''The treaty was signed by US President Barack Obama and Russian counterpart Dmitry Medvedev in Prague in 2010. It expires in 2021.</span><br />