WASHINGTON — The Obama administration denounced as illegal a planned weekend referendum by pro-Russian insurgents pushing for autonomy and independence for portions of eastern Ukraine.

Secretary of State John Kerry said Tuesday the referendum being planned for Sunday would be "bogus" and would not be recognized by the West.

"We flatly reject this illegal effort to further divide Ukraine," he told reporters after meeting at the State Department with EU foreign policy chief Catherine Ashton.

"This is really the Crimea playbook all over again and no civilized nation is going to recognize the result," he said, referring to the Moscow-supported March 16 independence referendum in the strategic Ukrainian peninsula that led to Russia's annexation of the strategic Ukrainian peninsula.

Although Russia has de facto control over Crimea, few nations recognize the move and the United States and Europe have hit Russia with sanctions over the annexation, and Moscow's continued actions in

U.S. officials have said all Ukrainians should vote on their future governance in nationwide elections set for May 25.