Moscow suspends agreements on research and development cooperation between Russia and the United States in nuclear and energy sectors, reports the  RIA Novosti, referring to the governmental source. 

According to the Russian government, in April 2014, Rosatom received a letter from the US Bureau of Energy Resources through the US Embassy in Moscow, which states  Washington's decision to stop nuclear cooperation with Russia in the energy sector, in connection with the events in Ukraine.

 “This step by the US is a substantial violation of the terms of the Agreement that is designed to expand cooperation in nuclear energy research and development and provide a stable, reliable and predictable foundation for this cooperation,” states the Russian governmental web-site.