Medvedev, responding to U.S. moves to establish an anti-missile shield in Eastern Europe, said Friday during military exercises in the southern Urals region of Orenburg that "a guaranteed nuclear deterrent system for various military and political circumstances must be provided by 2020," The Times of London reported.

Medvedev also called for Russia to reorganize its military, saying "all combat formations must be upgraded to the permanent readiness category" by 2020, an effort that would include "mass production of warships, primarily nuclear cruisers carrying cruise missiles and multi-purpose submarines," The Times said.

Also attending the Orenburg exercises was Venezuelan President Hugo Chavez, whose country conducted joint naval exercises in the Caribbean Sea this week with Russian warships.

The Kremlin issued a statement calling the maneuvers a "counterweight to U.S. influence," and adding that Chavez was seeking "a widening of our presence in the region."