"These statements by Minister Shoigu are completely untrue," RIA Novosti quoted Kirby as saying.
He added that the head of the Pentagon, Lloyd Austin, did not discuss with his Russian counterpart the topic of exacerbating tensions around Ukraine.
Earlier, Shoigu said that American private military companies (PMCs) are preparing provocations with chemicals in the Donbass.
According to him, the presence of more than 120 employees of American PMCs was established in the settlements of Avdeevka and Priazovskoe in the Donetsk region of Ukraine.
The minister also spoke about the build-up of the US military presence at the Russian borders.