An aide to Russian deputy prime minister, Dmitry Rogozin, was among the first to tweet about the YouTube video, which shows photos of Nuland and Pyatt and is subtitled in Russian.
In the tweet, posted some seven hours before existence of the video became widely known on Thursday, the Rogozin aide, Dmitry Loskutov, opined: "Sort of controversial judgment from Assistant Secretary of State Victoria Nuland speaking about the EU."
State Department spokeswoman Jen Psaki did not dispute the authenticity of the recording and said that Nuland had apologized to European Union officials for her remarks.
Psaki said, however, that Moscow's apparent role in publicizing the video was "a new low in Russian tradecraft."
The YouTube video was posted on Feb. 4 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 center of opposition protests.
In the audio, Nuland and Pyatt discuss their views of various opposition figures and whether or not they should take positions in the government.
The U.S. has repeatedly denied allegations, many of them from Russian officials, that it is taking sides in the Ukraine crisis and Psaki repeated that stance on Thursday.
"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," Psaki said. "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," she said. "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."