Washington’s new top diplomat for Europe, Victoria Nuland, apologized Thursday to EU counterparts after she was caught cursing about the European response to the crisis in Ukraine in a bugged phone call.

US officials, while not denying such a conversation took place, refused to go into details, and pointed the finger at Russia for allegedly bugging the diplomats’ phones.

While Psaki said she had no independent details of how the conversation was captured and uploaded onto the social networking site, she added: “Certainly we think this is a new low in Russian tradecraft.”

White House spokesman Jay Carney alleged that the fact that it had been “tweeted out by the Russian government, it says something about Russia’s role.”

Nuland, who took over late last year as assistant secretary for European affairs, and Pyatt appear to discuss President Viktor Yanukovych’s offer last month to make opposition leader Arseniy Yatsenyuk the new prime minister and Vitaly Klitschko, deputy prime minister. Both men turned the offer down.

Nuland, who in December went down to Independence Square in Kiev in a show of support for the demonstrators, adds she has also been told that the UN chief Ban Ki-moon is about to appoint a former Dutch ambassador to Kiev, Robert Serry, as his representative to Ukraine.

Psaki sought to downplay any tensions with the European Union over Ukraine, which has been rocked by weeks of protests by pro-democracy protestors.

Demonstrators were angered by Yanukovych’s sudden decision last year to abandon moves to sign an association accord with the EU, and instead solicit a financial aid package from former Soviet master, Russia.

Psaki said the United States, which is mulling possible sanctions on Ukraine if it cracks down on the protests, has “been working closely” with the EU.

She also disputed Russian allegations that Washington was meddling in Kiev’s internal politics.

Nuland is heard saying of Klitschko, “I don’t think Klitsch should go into the government. I don’t think it’s necessary. I don’t think it’s a good idea.”

But Psaki said it should be “no surprise that US officials talk about issues” adding it was a “private diplomatic conversation.”

The phone tapping was an ironic twist on a spying scandal which soured relations with the EU last year, after it was revealed that US intelligence agencies had been gathering data from European leaders’ phones.

Nuland meanwhile met Thursday in Kiev with Yanukovych, who told her that he wanted to quickly adopt constitutional changes called for by pro-Western demonstrators.