US and Russian leaders hail nuclear arms treaty

US President Barack Obama and his Russian counterpart, Dmitry Medvedev, have signed a landmark nuclear arms treaty in the Czech capital, Prague.

The treaty commits the former Cold War enemies to each reduce the number of deployed strategic warheads to 1,550 - 30% lower than the previous ceiling.

Mr Obama said it was an important milestone, but "just one step on a longer journey" of nuclear disarmament.

Mr Medvedev said the deal would create safer conditions throughout the world.

If ratified by lawmakers in both countries, the treaty will replace the Strategic Arms Reduction Treaty (Start) of 1991, which has expired.