Russia demanded at the United Nations on Thursday that the United States and Britain provide evidence to support their allegations that Moscow was seeking drones from Iran and rockets and artillery shells from North Korea to use in Ukraine.
"I would like to ask them now to either provide us with evidence or acknowledge that they are disseminating unreliable information," Russia's UN Ambassador Vassily Nebenzia told the 15-member Security Council.
The United States has accused Iran of supplying drones to Russia for use in its war in Ukraine, which Tehran has denied. Washington also accused Moscow of being "in the process" of purchasing millions of rockets and artillery shells from North Korea, deputy US Ambassador Richard Mills told the council.
"Russia is turning to Iran to supply UAVs (unmanned aerial vehicles) and, in a clear violation of UN sanctions, to North Korea to supply ammunition," Britain's UN Ambassador Barbara Woodward said.
Russia called the Security Council meeting on Ukraine - the body's third in as many days - to discuss the supply of foreign weapons to Kyiv. The United States, Britain, France and others defended the billions of dollars in military assistance delivered to Ukraine since Russian forces invaded on Feb 24.
"Russia's claims that the United States and the 'West' is escalating and prolonging this conflict are false," Mills said. "They are cynical attempts to deflect attention from Moscow's role as the sole aggressor in what is unnecessary and brutal war, for which the world is paying a collective price."
Russian President Vladimir Putin calls the invasion a "special military operation" to disarm its neighbor and attempt to preemptively protect his country's security against the expansion of NATO, the Western military alliance.
Ukraine on Thursday hailed a lightning counteroffensive it said had recaptured swathes of its territory in the east and south, as US Secretary of State Antony Blinken visited the country to pledge further aid.
"We are very far still from the end of this destructive process," Nebenzia told the council. "Western weaponry is not playing a decisive role on the battlefield, regardless of what the Ukrainians and their vassals are saying."
Ukraine's UN Ambassador Sergiy Kyslytsya said: "We will fight against the occupiers until all the Russian soldiers who entered Ukraine to kill its people are defeated."