Moscow needs \"solid legal guarantees\" that a European missile defense shield wouldn\'t alter the balance of power, UPI quoted Russian Foreign Minister Sergei Lavrov as saying. Speaking before the 66th session of the U.N. General Assembly in New York, the top Russian diplomat said the potential of a U.S.-backed missile defense system in Europe to compromise Moscow\'s security is \"far too serious\" to gloss over. Dismissing verbal assurances by the United States and NATO that such a European system wouldn\'t undermine the continent\'s strategic stability as \"not enough,\" Lavrov declared Moscow needed such assurances in writing. \"We need solid legal guarantees that missile defense potential will actually be adequate to the declared objectives and will not disrupt global and regional balances,\" he said. \"This equally holds true both for Europe and for the Asia-Pacific region, where ballistic missile defense is becoming a factor that affects the strategic environment.\" Lavrov reiterated Russian fears that a missile defense based in Eastern Europe could be used to target its own nuclear deterrent force of intercontinental ballistic missiles. Russia and NATO have been talking since last year to reconcile conflicting visions of European missile defense. Moscow prefers a single system covering all of Europe that would be operated jointly by Russia and NATO with full interoperability. NATO, however, backs two independent systems that would exchange information. Lavrov said it is ultimately the halt of the spread of nuclear weapons that will bring security to Europe and elsewhere. To that end, he called for the \"universalization\" of the 1970 Treaty on Non-Proliferation of Nuclear Weapons.