Moscow says the Biden administration was responsible for missile attacks on civilian targets in areas controlled by Russian-backed forces in eastern Ukraine.
Russia has said that the United States, the world's top military power, was directly involved in the conflict in Ukraine because US spies were approving and coordinating Ukrainian missile strikes on Russian forces.
Russia's defence ministry, headed by a close ally of President Vladimir Putin, on Tuesday said Vadym Skibitsky, Ukraine's deputy head of military intelligence, had admitted to the Telegraph newspaper that Washington coordinates HIMARS missile strikes.
"All this undeniably proves that Washington, contrary to White House and Pentagon claims, is directly involved in the conflict in Ukraine," the defence ministry said.
US President Joe Biden has said he wants Ukraine to defeat Russia and has supplied billions of dollars of arms to Kiev but US officials do not want a direct confrontation between US and Russian soldiers.
Russia said the Biden administration was responsible for missile attacks on civilian targets in areas controlled by Russian-backed forces in eastern Ukraine.
"It is the Biden administration that is directly responsible for all Kiev-approved rocket attacks on residential areas and civilian infrastructure in populated areas of Donbass and other regions, which have resulted in mass deaths of civilians," the defence ministry said.
Russian Defence Minister Sergei Shoigu said the operation in Ukraine was going to plan with Russian and Russian-backed forces pushing back Ukrainian forces in the eastern Donetsk region.
"After taking control of the territory of the Luhansk People's Republic, the Donetsk People's Republic is being liberated as planned," Shoigu told top generals.
He said the settlements of Hryhorivka, Berestove, Stryapivka, Pokrovske, Semyhirya and Novoluhanske had been taken recently, including the largest thermal power plant in Europe.
Russia's attack on Ukraine has triggered the most serious crisis in relations between Russia and the West since the 1962 Cuban Missile Crisis, when many people feared the world was on the brink of nuclear war.
Kremlin: Nuclear arms control talks hinge on US goodwill
The Kremlin said on Tuesday that it's ready for talks with the United States on nuclear arms control even as Moscow and Washington have remained locked in a tense standoff over Russia's actions in Ukraine.
Commenting on Biden’s statement that Washington is open for talks on a new arms control deal to replace the New START treaty after it expires in 2026, Kremlin spokesperson Dmitry Peskov said that such negotiations are long overdue.
Just days before the New START was due to expire in February 2021, Russia and the United States agreed to extend it for another five years.
The treaty, signed in 2010 by President Barack Obama and Russian President Dmitry Medvedev, limits each country to no more than 1,550 deployed nuclear warheads and 700 deployed missiles and bombers, and envisages sweeping on-site inspections to verify compliance.