The U.S. and six other nations say they are suspending participation in the planning for an international summit in Russia this summer.
The White House issued the joint statement on behalf of the Group of Seven. That's the U.S., Canada, France, Germany, Italy, Japan, and the United Kingdom. The nations also participate in the Group of Eight economic group, which includes Russia.
In the joint statement, the countries say they condemn Russia's "clear violation of the sovereignty and territorial integrity of Ukraine." They say Russia's advances in Ukraine violate the "principles and values" on which the G-7 and G-8 operate.
Russia is scheduled to host the G-8 summit in June in Sochi, site of the recently completed Winter Olympics.