President Vladimir Putin says Russia will add more than 40 intercontinental ballistic missiles to its nuclear arsenal in 2015.

Speaking at an arms fair, Putin said the weapons would be able to overcome even the most technically advanced anti-missile defence systems.

It comes after the US proposed increasing its military presence in Nato states in Eastern Europe.

Tensions are high over Russia's role in the conflict in eastern Ukraine.

Nato and Western leaders accuse Russia of sending soldiers and heavy weapons including tanks and missiles to the pro-Russian separatists in eastern Ukraine. Russia has repeatedly denied this, insisting that any Russians fighting there are "volunteers".

'ARMS RACE'

Russian officials have warned that Moscow will respond if the US carries out its plan to store heavy military equipment in Eastern Europe, including in the Baltic states that were once part of the Soviet Union.

"The feeling is that our colleagues from Nato countries are pushing us into an arms race," RIA news agency quoted Russian Deputy Defence Minister Anatoly Antonov as saying on the sidelines of the arms fair outside Moscow.