A senior Russian official has warned that Moscow it won't sit idly by and let the United States cozy up to the opposition in crisis-hit Ukraine, and even threatened Russian intervention to maintain the security of its ex-Soviet neighbor.
Russian President Vladimir Putin's top advisor on Ukraine, Sergei Glazyev, told a Ukrainian newspaper that Washington's "interference" in Ukraine was a clear breach of a 1994 treaty under which Washington and Moscow jointly guaranteed Ukraine's security and sovereignty.
Glazyev said Moscow might be obliged to step in, but he didn't specify on what action Russia might take.
Responding to the remarks, the White House said the U.S. was committed to working with both the Ukrainian government and the opposition to resolve the crisis.
Ukrainian President Viktor Yanukovich is in Sochi for the opening of the Winter Olympics and is set to meet with Putin on Friday.