Russia Opposes Imbalance of Strategic Nuclear Deterrence as Obama Proposes Arms Cuts

President Barack Obama said Russian and U.S. nuclear weapons should be slashed by up to a third in a keynote speech in front of Berlin's iconic Brandenburg Gate in which he called for a world of "peace and justice".

Obama used the once divided city's rebirth as a metaphor for progress, as he stood on the east side of the route of the Berlin Wall, and warned the "complacent" West that history did not stop with its Cold War victory.

"The wall belongs to history. But we have history to make as well," a sweat-streaked Obama said to an invited crowd of 6,000 people standing before the majestic landmark in sweltering summer weather.

The U.S. leader called on Russia to agree to bring the number of strategic nuclear weapons held by the former Cold War foes down to around 1,000 and to also cut stocks of tactical nuclear arms.

"I've determined that we can ensure the security of America and our allies and maintain a strong deterrent while reducing our strategic weapons by up to one-third," Obama said.

"These are steps we can take to create a world of peace and justice," he said, seeking to cement nuclear arms reductions as a key piece of his legacy.

Meanwhile, Russian President Vladimir Putin said on Wednesday that Russia will not allow for an imbalance in strategic nuclear deterrence, speaking ahead of a speech by U.S. President Barack Obama about major new arms reductions.

"We cannot allow the balance of the system of strategic deterrence to be disturbed or the effectiveness of our nuclear force to be decreased," Putin was quoted by Russian agencies as saying at a government meeting while discussing Russia's military space program.

Russian Deputy Prime Minister Dmitry Rogozin poured cold water on the proposal.

"How can we take seriously this idea about cuts in strategic nuclear potential while the United States is developing its potential to intercept this strategic potential?" he said, according Russia's Itar-TASS news agency.

A Kremlin spokesman said earlier that Russia had told the United States it wanted other nuclear armed states to commit to reductions.