(Refiles to fix spelling of secede in second paragraph)
WASHINGTON, March 6 (Reuters) - A planned referendum in Ukraine's Crimea region on whether to join Russia is completely illegitimate and violates the Ukrainian constitution, a U.S. State Department spokeswoman said on Thursday.
"To be clear, the premise that Crimea could hold a local referendum or vote in their local parliament to secede from Ukraine and join Russia is completely illegitimate under Ukraine's constitution," State Department spokeswoman Jen Psaki told a briefing.
(Reporting by Arshad Mohammed; Editing by Bill Trott)
Our Standards: The Thomson Reuters Trust Principles.