The 46th US President said: “Your family budget, your ability to fill up your tank – none of it should hinge on whether a dictator declares war and commits genocide half a world away.
“I called it genocide because it has become clearer and clearer that Putin is just trying to wipe out the idea of being able to be Ukrainian and the evidence is mounting.
“We’ll let the lawyers decide internationally whether or not it qualifies, but it sure seems that way to me.”
Mr Biden’s comments come days after Ukraine accused Russia of killing 50 people at a train station in the eastern town of Kramatorsk
There have also been reports of the killing of civilians in a number of towns close to Kyiv, most notoriously Bucha, which have drawn worldwide condemnation.
Ukrainian President Volodymyr Zelensky has previously said that the atrocities in Bucha constituted a “genocide” – a charge that other European leaders have repeated.
However, until now the Biden administration has previously stopped short of using the word genocide due to its strict legal definition and implications it carries.
Experts have warned about using the term with Juan Mendez former UN special adviser on the prevention of genocide, telling Al Jazeera that civilian deaths do not by themselves constitute a genocide.
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He said: “True words of a true leader @POTUS. Calling things by their names is essential to stand up to evil.
“We are grateful for US assistance provided so far and we urgently need more heavy weapons to prevent further Russian atrocities.”