UPDATE 1-Expulsion of EU delegation's chief in Venezuela further isolates Maduro -U.S.

(Updates with EU expulsion of Venezuela envoy)

WASHINGTON, Feb 25 (Reuters) - Venezuela's decision to ask the head of the European Union's delegation in Caracas to leave the country further isolates Nicolas Maduro's government, the State Department said on Thursday.

"The Maduro regime has removed one of the international champions standing up for democracy in Venezuela and human rights of the Venezuelan people," State Department spokesman Ned Price said.

"This action will only further isolate the Maduro regime and the world remains united in calling for a return to democracy in Venezuela," he added.

The European Union later on Wednesday declared Venezuela's envoy to Brussels persona non grata.

It said in a statement that the Maduro government's expulsion of its ambassador was "wholly unwarranted and contrary to the EU's objective of developing relations and building partnerships in third countries."

Claudia Salerno, Venezuela's representative to the EU, responded on Twitter by saying: "The independence and sovereignty of our Fatherland cannot be negotiated. Venezuela must be respected." (Reporting by Simon Lewis; Additional reporting by Daphne Psaledakis, Mohammad Zargham and Idrees Ali; Editing by Jonathan Oatis and Peter Cooney)