Russia has voiced concerns over U.S. plans to station additional nuclear weapons in Germany's Luftwaffe's Büchel Air Base, according to the German TV station ZDF, which reported earlier on Tuesday that the U.S. is planning to bring 20 nuclear B-61 bombs to the country.

"We are concerned that these states actually have nuclear weapons as part of the framework of NATO's nuclear sharing program," Russian Foreign Ministry spokeswoman Maria Zakharova told ZDF on Tuesday, according to The International Business Times.

Zakharova said the decision would violate the Treaty of Nonproliferation of Nuclear Weapons, an arms limitation and disarmament agreement ratified by 191 countries in 1970 to prevent the spread of nuclear weapons.

"The comprehensive analysis of the situation points to the threat posed by the increasing military capability of NATO and its endowment with global functions, which it performs in violation of the international law, as well as the encroachment of the military infrastructure of NATO members on the borders of the Russian Federation," she said, according to RT.

Zakharova claims that Russia has reduced its non-strategic nuclear stockpiles fourfold since the 1990s, but says the U.S. hasn't followed suit.

"At the same time in Europe -- not just in Germany, but also in Belgium, the Netherlands, Italy and Turkey -- U.S. tactical nuclear armaments remain deployed," Zakharova, said, according to the Russian news site Sputnik. "The Americans are modernizing their aerial bombs, and the NATO European members are modernizing their aircraft that carry these weapons."

Through a NATO sharing program, the U.S. continues to store nuclear weapons in facilities in some European countries. As part of the program, host countries conduct consultations, craft weapons policies and maintain equipment essential to the delivery of nuclear weapons, such as bomber planes, according to the International Business Times.

President Obama revealed in Sept. 2014 that the U.S. plans to spend $1 trillion over the next three decades to revamp its nuclear arsenal, reported The New York Times.

Some German lawmakers previously called on its government to have America remove tactical nuclear weapons from the country, according to Deutsche Welle.