U.S. Assistant Secretary of State Victoria Nuland has refused to comment on a leaked telephone conversation in which she used vulgar language about the European Union.
Nuland said Friday she would not talk about what she called a "private diplomatic conversation," but said the recording was "impressive tradecraft" - a term referring to activity by intelligence agents.
In the call with U.S. Ambassador to Ukraine Geoffrey Pyatt, Nuland used foul language to suggest that the United States should ignore the European Union's position on resolving the crisis in Ukraine.
State Department spokeswoman Jen Psaki said the phone conversation does not reflect how Nuland feels about the EU. She said Nuland has been in close touch with EU officials on the situation in Ukraine.
Ukrainian President Viktor Yanukovych and Russian President Vladimir Putin met behind closed doors in the Olympic city of Sochi on Saturday, but a Ukrainian official would not give any details about the meeting. Mr. Yanukovych triggered mass protests in November when he yielded to Russian pressure and backed out of a free trade pact with the EU. Protesters continue to camp out in Kyiv.
U.S. officials have implied Russia may be involved in the leak, which was posted on the YouTube website.
U.S. officials on Thursday pointed to a Tweet by an aide to Russian Deputy Prime Minister Dmitry Rogozin as the first to promote the recording.
In comments to the Associated Press, Rogozin's office denies involvement.
German Chancellor Angela Merkel calls Nuland's comments about the EU totally unacceptable. She also praised the work of EU foreign affairs chief Catherine Ashton, who has led the EU effort toward a settlement in Ukraine.