This video appears to feature a phone call by U.S. Assistant Secretary of State Victoria Nuland to Geoffrey Pyatt, U.S. ambassador to Ukraine. Caution: Video contains profanity.

The top U.S. diplomat for Europe apologized Thursday for comments about the European Union that were — to put it lightly — undiplomatic.

“F--- the E.U.,” Assistant Secretary of State for European and Eurasian Affairs Victoria Nuland said in a private telephone call that was intercepted and leaked online.

In the call, Nuland, a former U.S. ambassador to NATO and State Department spokeswoman, was dismissively referring to slow-moving European efforts to address political paralysis and a looming fiscal crisis in Ukraine. But it was the blunt nature of her remarks, rather than U.S. diplomatic calculations, that seemed exceptional.

Nuland also assessed the political skills of Ukrainian opposition figures with unusual candor and, along with the U.S. ambassador to Ukraine, Geoffrey Pyatt, debated strategy for their cause, laying bare a deep degree of U.S. involvement in affairs that Washington officially says are Ukraine’s to resolve.

State Department spokeswoman Jen Psaki acknowledged that the recording was authentic and said Nuland had apologized to E.U. officials. But U.S. officials were also quick to point the finger at Russia, which has bristled at U.S. involvement in Ukraine.

The recording “was first noted and tweeted out by the Russian government. I think it says something about Russia’s role,” White House press secretary Jay Carney told reporters.

The recording surfaced on YouTube on Thursday, just as Nuland arrived in Ukraine for talks. It was also widely viewed on a Russian-language Web site, where it appeared online along with a photo montage of Nuland, Pyatt, and opposition figures. The Russian caption reads, “Puppets of the Maidan,” the colloquial name for Kiev’s Independence Square.

[Read: A quick guide to who’s who on the call]

Illicitly recorded material is a staple of politics in former Soviet republics, where it’s known by its Russian name “kompromat,” meaning “compromising materials.”

The political crisis in Ukraine erupted last fall, when President Viktor Yanukovych abruptly pulled out of a trade partnership with the European Union and announced that the country would join a Russian economic alliance instead. That offer came with a $15 billion loan that U.S. and European officials came close to calling a bribe.

Russia had threatened Ukraine with trade sanctions if it signed the E.U. pact and made little secret of its desire to retain influence over Ukraine and Yanukovych, who was the Kremlin’s preferred candidate when he was elected in 2010.

Russia has lent about $3 billion, but suspended the balance of the loan after Yanukovych's political concessions to the opposition last month.

The European Union’s foreign policy chief visited Kiev this week with new offers of financial help for Ukraine’s growing economic problems. The package is widely seen as an effort to counter Russian influence.

The State Department did not say exactly when the recorded conversation took place, but it came after Yanukovych's Jan. 25 offer to include two senior members of the opposition movement in his government.

Long before Nuland’s visit this week, Russia accused Washington of meddling in the affairs of one of its close neighbors and of inappropriately championing the opposition cause. The substance of the Nuland conversation is sure to increase those complaints.

Nuland and Pyatt speak like political strategists, or perhaps like party bosses in a smoky back room. Using shorthand and nicknames, they game out what they would like to see opposition figures do and say, and discuss how best to influence some opposition decision-making.

They also refer to personality problems and rivalries among the three top opposition figures.

Nuland bluntly says she does not want to see opposition leader Vitali Klitschko join the government, and Pyatt agrees.

“I don’t think it’s necessary,” she says. “I don’t think it’s a good idea.”

She says another leader, “Yats,” has the economic experience that both the Americans apparently think Klitschko lacks. That is apparently a reference to opposition leader Arseniy Yatsenyuk, who was offered the post of prime minister. Klitschko was offered the post of deputy prime minister. Both men declined.

Pyatt tells Nuland he is glad she put Yatsenyuk “on the spot about where he sort of fits in this scenario” during a phone conversation and suggests whom she should call next.

The conversation ends with Nuland offering to arrange a phone call from Vice President Biden to help keep pressure on Yanukovych. Biden, she says, can give an “attaboy.” Biden and Yanukovych have spoken several times over the past month.

On Thursday, Psaki said the discussion is not evidence of any American plan to influence the political outcome.

“It shouldn’t be a surprise that at any point there have been discussions about recent events and offers and what is happening on the ground,” Psaki said.

Nuland met Thursday with Yanukovych and with opposition leaders.

Ukrainian protesters have criticized the country’s parliament as ineffective, and Yanukovych’s office released a statement saying he “would do everything to prevent escalation of the conflict.”