The White House has again dismissed Russia's allegation that Ukraine was involved in the attack on the Crocus City concert hall and said that the United States had passed clear and detailed information to Russian security services about an extremist attack in Moscow in advance of the attack.
White House National Security Council spokesman John Kirby said on March 28 that Russia's charge of Ukrainian involvement in the attack was “nonsense and propaganda."
Kirby spoke shortly after Russia's Investigative Committee said it had uncovered evidence that the four gunmen who carried out the attack on March 22, which killed more than 140 people were linked to Ukraine.
"It is abundantly clear that [Islamic State] was solely responsible for the horrific attack in Moscow last week," Kirby said, reiterating the U.S. position, which is shared by France. "In fact, the United States tried to help prevent this terrorist attack and the Kremlin knows this."
The written message to Russia's security services was passed on March 7 at 11:15 a.m. and was one of multiple advance warnings that the United States provided to Russian authorities about the potential for extremist attacks on concerts and large gatherings in Moscow, Kirby said.
The messages were passed "following normal procedures and through established channels that have been employed many times previously,” he said, emphasizing his rebuke of Russian officials by comparing them to "manure salesmen" who "carry their samples in their mouths."
Islamic State has said several times that it was responsible for the attack, and IS-affiliated media channels have published graphic videos of the gunmen inside the venue.
Despite the IS claim of responsibility and the information released by the United States, Russian President Vladimir Putin and other Russian officials have persisted in trying to implicate Ukraine. Russia's Investigative Committee claimed on March 28 that suspects in the attack had "links with Ukrainian nationalists."
"As a result of work with the detained terrorists, an examination of technical devices seized from them and analysis of financial transactions, evidence of their links with Ukrainian nationalists has been obtained," the Investigative Committee said in a statement.
It alleged that the suspects had received "significant amounts of money and cryptocurrency from Ukraine" and said another man "involved in financing the terrorists" had been identified and detained and investigators would ask the court to remand him in custody. No other details were provided.