A suspension decree signed by Prime Minister Dmitry Medvedev was posted Wednesday on the government website, which said the decree was a "countermeasure" to U.S. sanctions imposed over Russia's role in the Ukraine conflict. The government also said on its website that an agreement between the state nuclear energy firm Rosatom and the U.S. Department of Energy on feasibility studies into conversion of Russian research reactors from highly-enriched to low enriched uranium had been terminated. Following weeks of deteriorating diplomatic efforts between the U.S. and Russia over Syria — to the point where the U.S. has now placed additional military options on the table — Russian President Vladimir Putin suspended a nuclear pact with Washington on Monday, Reuters reports, indicating his willingness to play the nuclear card with the United States. “But on Monday, Putin issued a decree suspending an agreement, concluded in 2000, which bound the two sides to dispose of surplus plutonium originally intended for use in nuclear weapons.”

Putin’s decree, released by the Kremlin on Monday, cites “unfriendly acts” by Washington as motivating factors for the move. While the United States has imposed economic sanctions on Russia for its actions in Ukraine, these have yet to force it to calm tensions in eastern Ukraine, let alone surrender Crimea.
Russian President Vladimir Putin suspends the 2013 nuclear agreement with the United States concerning uranium research.