Russia says it is outraged by an interview with Chechen rebel leader Shamil Basayev broadcast on America's ABC television network.
Russia has put a $10m bounty on Shamil Basayev's head
The Russian foreign ministry summoned a senior US diplomat in Moscow to express its "strong indignation" over the show.
In the interview, the warlord, who had claimed the 2004 raid on a school in Beslan, admitted he was a terrorist but said the Russians were terrorists too.
Russia's most wanted man also warned of further Beslan-type attacks.
More than 320 people - around half of them children - were killed in the attack at the school in September.
Russia is offering $10m (£6m) for the capture of the warlord, who it also accuses of several other major attacks.
The interview with Shamil Basayev - recorded at his hideout in Chechnya - was aired on ABC's Nightline programme on Thursday.
Many children were hurt in a gun battle as the Beslan siege ended
The Russian foreign ministry said on Friday it summoned the US Charge D'Affaires, Daniel Russell, to express its "strong indignation with the fact of the airing of the Basayev interview".
On Thursday, the Russian embassy in Washington said ABC's apparent decision to ignore Moscow's arguments against broadcasting the material was deplorable.
Its statement said the Chechen rebel leader was "responsible for slaughtering innocent victims during many major terrorist attacks that he masterminded and personally perpetrated".
"The most shocking and deadliest of them was the cold blooded killing of hundreds of children" in Beslan.
The interview "runs counter to the spirit of Russian-American partnership in our joint fight against the global threat of terrorism", the embassy said in the statement, which was also broadcast by ABC.
In the interview, Mr Basayev - speaking through an interpreter - admitted that he was "a bad guy, a bandit".
"Ok, so I'm a terrorist, but what would you call them (the Russians)?
"If they are the keepers of constitutional order, if they are anti-terrorists then I spit on all these agreements and nice words," he said.
The warlord accused Russia of killing thousands of Chechen women, children and old people in what he described as "a colonial war".
When asked if Beslan-style attacks could happen again, he said: "Of course they can. As long as the genocide of the Chechen nation continues... anything can happen."
The warlord also refused to accept responsibility for the deaths of children killed in Beslan, blaming instead Russian authorities.