Russia-U.S. strategic nuclear arms cuts cannot be pursued without also addressing missile defense systems, Foreign Minister Sergei Lavrov said Thursday, June 20, according to RIA Novosti.

Strategic stability is affected by the role of defense systems, in particular “the U.S. plans to build non-nuclear weapons” which will be “far more effective than the existing strategic nuclear arms,” he said in an interview with Rossia-24 TV.

Further cuts in nuclear weapons can only be discussed in a multilateral, not bilateral format, with the participation of other nuclear powers, Lavrov said.

In a wide-ranging speech Wednesday in Berlin, U.S. President Barack Obama said he has concluded after “a comprehensive review,” that the United States can cut its deployed strategic nuclear weapons by one-third while still ensuring the nation’s security. “And I intend to seek negotiated cuts with Russia to move beyond Cold War nuclear postures,” Obama said.

Lavrov also said the U.S. review of its missile defense program for Europe does not address Russia’s concerns because “the system remains global” and its components “are being deployed along the perimeter of our borders.”

Russia and NATO formally agreed to cooperate over the European missile defense system at the 2010 NATO summit in Lisbon, but talks foundered, in part over Russian demands for legal guarantees that the system would not undermine its strategic nuclear deterrent. In mid-March, the U.S. announced that it was modifying its planned missile defense deployment to Poland, dropping plans to station SM-3 IIB interceptors in the country by 2022.