Speaking Tuesday 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 and Turkey -- which the West says is needed to counter threats from Iran and the Middle East -- 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, to which Israel, Pakistan, India and North Korea aren't signatories.
He also called for a strengthening of International Atomic Energy Agency's safeguards system and the adoption of the Comprehensive Nuclear-Test-Ban Treaty, which Indonesia, Iran, Egypt, China, Israel and the United States have signed but not ratified.
The Russian foreign minister's speech came only hours after the country's deputy defense minister reported continued slow going in negotiations between Moscow and NATO in the missile shield talks.
Deputy Defense Minister Anatoly Antonov said in New York that although Russia was "ready for compromises within reason" on the issue, "no breakthrough decisions" had been made, RIA Novosti reported.
"Our U.S. partners continue implementing their plans to create the European segment of the U.S. missile defense system," Antonov said.
NATO Secretary-General Anders Fogh Rasmussen said last week he expected Russia and the Western military alliance to agree on missile defense at its May 2012 summit in Chicago.
Antonov claimed Washington, rather than NATO, is quickly driving the establishment of the anti-missile shield at "a pace that strongly exceeds the discussions between Russia, NATO and the United States."
Turkey has agreed to host an early warning radar as part of the missile defense shield against and Poland will install other elements by 2018. Romania and the Czech Republic would also host parts of the system under the "European Phased Adaptive Approach" plans.