Russia suspended a nuclear cooperation agreement with the United States as a countermeasure to anti-Russian sanctions related to the conflict in Ukraine, just days after the two countries broke off engagement on the Syrian ceasefire.

On October 5, 2016, the Russian government announced its decision to suspend the U.S.-Russia agreement on nuclear and energy-related research and development work, signed in Vienna on September 16, 2013.

Moscow cited the introduction of sanctions against Russia by the United States following the events in Ukraine, along with the subsequent violation of the terms of the agreement by the U.S. side, as the reasons for its decision.

According to the directive, an agreement between Russia’s Rosatom nuclear corporation and the U.S. Department of Energy on studying the feasibility of converting six Russian scientific reactors to low-enriched uranium fuel has been terminated as part of the suspension.

The document said actions taken by the United States in introducing sanctions against Russia in connection with the events in Ukraine have directly affected the areas of cooperation under the agreement.

“The repeated extension of U.S. sanctions against Russia, including the suspension of U.S.-Russia nuclear energy cooperation, requires the adoption of countermeasures in relation to the U.S.,” the directive said.

The Russian Foreign Ministry said Moscow would consider resuming nuclear energy collaboration with Washington if the United States vows to implement all of the document’s provisions.

White House Press Secretary Josh Earnest told reporters after the announcement that the United States hoped to continue cooperating with Russia on issues of nuclear security because they were critical to the country’s national interest.

“We would regret the Russian decision to unilaterally suspend cooperation on what we believe is a very important issue,” Mark Toner, the deputy spokesman for the U.S. State Department, stated.

Earlier on October 5, 2016, U.S. Assistant Secretary of State for European and Eurasian Affairs Victoria Nuland met with Russian officials in Moscow to discuss potential ways of making progress in implementing the Minsk peace accord.

Russia’s decision comes after the U.S. government suspended bilateral engagement on efforts to implement a ceasefire in Syria.