MOSCOW, October 7. /TASS/. Russia has suspended its agreement with the United States on the disposal of weapons-grade plutonium due to a drastic change of the situation, Russian Foreign Ministry's official spokeswoman Maria Zakharova said on Friday.

She cited the agreement’s provision providing for a possibility for either of the signatories to withdraw from the agreement in case of cardinal change of the situation. "You don’t have to be an expert to see that such a change has already taken place," she said in an interview with the Dozhd TV channel.

Russian President Vladimir Putin on October 3 signed a decree to suspend the plutonium disposal agreement with the United States. A relevant bill has been submitted to the State Duma for approval. And on October 5 Russian Prime Minister Dmitry Medvedev issued an instruction to freeze the Russian-US agreement in nuclear and energy research and development.

"Regular extension of the US sanctions against Russia, including suspension of Russia-US cooperation in the area of peaceful use of nuclear energy, requires counter measures against the American side," the explanatory note to the document said. However, according to the document, Russia reserves the right to "resume cooperation under the agreement when it is appropriate from the point of view of the general context of relations with the United States."

Meanwhile, Deputy State Department Spokesperson Mark Toner said Russia’s suspension of the plutonium disposal agreement was a real tragedy.

The agreement with the United States was signed on August 29, 2000. It envisaged ways of disposing of excessive weapons-grade plutonium in Russia and the United States, including the production of mixed oxide fuel to be used in nuclear power reactors, conversion into non-weapons-grade form and also burial. It was expected that either side will start eliminating "declassified" amounts of plutonium in an amount of 34 tonnes. Russia converts weapons-grade plutonium into fuel for nuclear power plants.