U.S. President Joe Biden said for the first time on Tuesday that Russia's invasion of Ukraine amounts to genocide, a significant escalation of the president’s rhetoric.

President Biden yesterday accused Russian President Vladimir Putin of committing “genocide" in Ukraine.

Media reports says Mr. Biden  made the accusation in a speech at an ethanol fuel plant in Iowa, where he blamed the Russian invasion for higher gas prices.

"Your family budget, your ability to fill up your tank, none of it should hinge on whether a dictator declares war and commits genocide a half a world away," President Biden was cited as saying by the National Public Radio (NPR).

Asked later what made him use the word "genocide," Biden replied, "Yes, I called it genocide. It has become clearer and clearer that Putin is just trying to wipe out the idea of even being — being able to be Ukrainian.” 

Biden reportedly said evidence against Putin and the Russian military was mounting.

Ukrainian President Volodymyr Zelenskiy reacted on Twitter to Biden's genocide remarks, saying that "Calling things by their names is essential to stand up to evil."

"We are grateful for US assistance provided so far," he continued, "and we urgently need more heavy weapons to prevent further Russian atrocities."

Meanwhile Russian President Vladimir Putin says Russia’s military operation in Ukraine is proceeding according to a plan and will continue until all its initial goals are achieved.

Russian media reports says he noted this yesterday when arrived at the Vostochny spaceport together with his Belarusian counterpart Alexander Lukashenko.

That said, according to him, talks with Kiev have again hit a wall because the Ukrainian side moved away from the agreements reached at a meeting in Istanbul at the end of March.

According to TASS, the leaders of Russia and Belarus in Vostochny met the representatives of the rocket and space industry, held three-hour talks and conducted a joint press conference.