US apology after EU Ukraine insult
7 February 2014 Last updated at 21:07 GMT
US official Victoria Nuland has apologised after she referred disparagingly to the EU's role in mediating the crisis in Ukraine during a conversation said to be with the US ambassador to the country.
A recording of the exchange was posted online, with the US hinting at Russia's involvement in bugging and leaking it.
The BBC's Rajesh Mirchandani reports.