A senior US diplomat has apologised after having allegedly been caught declaring “f*** the EU” over its position on Ukraine during an apparently bugged telephone conversation.

The US has since suggested Russia may have been involved in hacking the call after a tape of the alleged conversation between the top US diplomat for Europe, Victoria Nuland, and the US ambassador to Ukraine, Geoffrey Pyatt was made public via YouTube.

State Department spokeswoman Jen Psaki said that if Russia was responsible for listening to, recording and publishing a private diplomatic telephone conversation, it would be "a new low in Russian tradecraft".

Download the new Independent Premium app Sharing the full story, not just the headlines

When asked if the call was authentic, Ms Psaki would not directly confirm it was Ms Nuland's voice but said: "I didn't say it was inauthentic."

She said Mrs Nuland "has been in contact with her EU counterparts and of course has apologised for these reported comments".

"It is no secret that Ambassador Pyatt and Assistant Secretary Nuland have been working with the government of Ukraine, with the opposition, with business and civil society leaders to support their efforts," Ms Psaki continued. "It shouldn't be a surprise that at any points there have been discussions about recent events and offers and what is happening on the ground.

"Of course these things are being discussed. It doesn't change the fact that it's up to the people on the ground. It is up to the people of Ukraine to determine what the path forward it."

US officials noted that an aide to Russian deputy prime minister, Dmitry Rogozin, was among the first to tweet about the YouTube video, which has Russian subtitles.

In the audio, voices resembling those of Mrs Nuland and Mr Pyatt discuss international efforts to resolve Ukraine's ongoing political crisis.

At one point, the voice that sounds like Mrs Nuland's suggests that the EU's position should be ignored after she reportedly tells Mr Pyatt that Ban Ki-Moon, the UN secretary-general, is going to appoint Robert Serry, the former Dutch ambassador to Kiev as his representative in Ukraine. "That would be great I think to help glue this thing and have the UN glue it and you know, F*** the EU," the voice says.

Daily coronavirus briefing No hype, just the advice and analysis you need Enter your email address Continue Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid Email already exists. Log in to update your newsletter preferences Register with your social account or click here to log in I would like to receive morning headlines Monday - Friday plus breaking news alerts by email Update newsletter preferences

In a tweet, posted seven hours before the video became widely publicised on Thursday, the Rogozin aide, Dmitry Loskutov, suggested the conversation was "sort of controversial judgment from Assistant Secretary of State Victoria Nuland speaking about the EU."

White House spokesman Jay Carney pointed to the tweet and Russia's apparent interest in what has become a struggle between pro-Moscow and pro-Western camps in the former Soviet Republic, but did not comment on the source of the audio or the substance of the conversation as they "do not discuss private conversations".

"I would say that since the video was first noted and tweeted out by the Russian government, I think it says something about Russia's role," Mr Carney added.

A State Department official, speaking on condition of anonymity, said the audio sounded like an authentic recording of a call that occurred last week.

The YouTube video was posted on 4 February and is titled the "Marionettes of Maidan" in Russian.

Maidan is the name of the main square in the Ukrainian capital of Kiev, which has become the centre of opposition protests against the Ukraine government following its decision to strengthen ties with Russia over a political and trade deal with the European Union.

Additional reporting by Associated Press