Russia to upgrade nuclear systems
Russian President Dmitry Medvedev has announced plans to build a "guaranteed nuclear deterrent system", to be in place by 2020.
He said he wanted military chiefs to submit plans by December.
He called for a programme to build new nuclear submarines as well as "a system of aerospace defence".
The announcement comes just weeks after Russia accused America of starting a new arms race by siting part of its missile defence shield in Poland.
"We must guarantee nuclear deterrence under various political and military conditions by 2020," Mr Medvedev told military commanders.
He said it was necessary to build "new types of armaments", and to "achieve dominance in airspace", according to quotes carried by the Itar-Tass news agency.
"We plan to start serial production of warships, primarily nuclear-powered submarines carrying cruise missiles and multifunctional submarines," Mr Medvedev said.
"We will develop an aerospace defence system, as well," he added.
Moscow has repeatedly criticised the US for going ahead with plans for a missile defence shield, using rockets based in Poland and radar in the Czech Republic, saying it destabilises the strategic balance and builds "a ring of steel" around Russia.
Russia warned it would be "forced to react".
This, it seems, is Russia is showing its own determination to bolster its nuclear deterrent, says the BBC's defence correspondent Caroline Wyatt.