The United States on Tuesday denounced moves by pro-Russian separatist groups in eastern Ukraine to organize what it called a "bogus" referendum.

The United States on Tuesday denounced moves by pro-Russian separatist groups in eastern Ukraine to organize what it called a "bogus" referendum.

Comparing the May 11 plebiscite to an earlier vote that preceded Moscow's annexation of Crimea, State Department spokeswoman Jen Psaki said: "This is the Crimea play-book all over again."