Moscow condemned "provocative actions" after the US pledged a Patriot air defense system to Kyiv. Meanwhile, an intelligence report said Belarus was training newly mobilized Russian reservists.
Moscow on Thursday denounced Ukrainian President Volodymyr Zelenskyy's visit to Washington, claiming that it showed Kyiv was "not ready for peace."
Zelenskyy met with US President Joe Biden on Wednesday and addressed Congress in his first official trip outside of Ukraine since Russia launched the war in February.
Kremlin spokesman Dmitry Peskov told reporters that Moscow regretted that neither Biden nor Zelenskyy said "even a few words that could be perceived as potential readiness to listen to Russia's concerns."
Biden announced on Wednesday that the US would provide Kyiv with an additional security aid of $1.85 billion (€1.737 billion), including the Patriot air defense system.
Peskov said that this signaled that the US was "continuing its line of de facto fighting an indirect war with Russia to the last Ukrainian," adding that the Patriot missile would not deter Russia from achieving its goals in Ukraine.
In a statement issued by the Russian Embassy in the US on Thursday, Ambassador Anatoly Antonov's described Zelenskyy's visit as a "Hollywood-style trip."
"What was essentially announced [...] was the need to continue the 'proxy war' against our country," Antonov said.
The Russian envoy said the US supplying weapons to Ukraine was "deeply disturbing."He added that Moscow stressed that "the provocative actions by the US are steadily leading to an escalation, the consequences of which cannot even be imagined."