Russia’s President Vladimir Putin has unveiled plans to develop a new range of nuclear weapons unlike those held by other countries.Addressing a gathering of military chiefs, Putin said Russia was already under threat from international terrorism. But, he added, “we understand as soon as we ignore components of our defence such as a nuclear missile shield, other threats may occur”. He said they were testing systems of the kind other nuclear powers did not have and would not have in the near future. Although no details were immediately available, the new weapons should be in use within a few years, according to the president. Earlier this month Russian defence minister, Sergei Ivanov, mentioned plans to test-fire a mobile version of its Topol-M ballistic missile. And there have also been reports that Russia is developing a next-generation heavy nuclear missile. Russia has been seeking to upgrade its nuclear arsenal since the US announced in 2001 it was working on a missile defence shield. Moscow interpreted that decision as a breach of treaties between the two nations.