In a briefing on 28 March, White House National Security Spokesperson John Kirby dismissed Russia's allegations of Ukraine's involvement in the attack on Moscow's Crocus City concert hall as "nonsense." Kirby stated that the US had provided Russian security services with a written warning of a potential extremist attack on large gatherings in Moscow, among many other advanced warnings.
"It is abundantly clear that ISIS [Islamic State] was solely responsible for the horrific attack in Moscow last week. In fact, the United States tried to help prevent this terrorist attack and the Kremlin knows this," Kirby said.Kirby's comments came shortly after Russian investigators claimed that they had discovered proof linking the gunmen responsible for the deaths of over 140 individuals in last week's attacks to "Ukrainian nationalists."
John Kirby characterized the Russian allegations as "nonsense and propaganda." He stated that the US had provided multiple advance warnings to Russian authorities regarding potential extremist attacks targeting concerts and large gatherings in Moscow.
He said it was clear that Islamic State was "solely responsible."