Russia committing 'genocide' in Ukraine: Biden

US President Joe Biden for the first time has accused Russian President Vladimir Putin's forces of committing "genocide" in Ukraine by trying to wipe out the idea of even being a Ukrainian."

Biden made the remarks about Russia's actions during a speech in Iowa about his administration's efforts to combat high prices for goods.

His comments came as Putin vowed on Tuesday that Russia's bloody offensive in Ukraine would continue until its goals are fulfilled.

I'm doing everything within my power, by executive orders, to bring down the prices and address the Putin price hike. In fact, we've already made progress since the March inflation data was collected, Biden 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 a half a world away. To help deal with this Putin price hike, I've authorised the release of 1 million barrels per day for the next six months from our Strategic Petroleum Reserve, he said.

Later at the Des Moines airport, he defended his remarks.

Yes, I called it genocide. It has become clearer and clearer that Putin is just trying to wipe out the idea of even being - able to be Ukrainian, Biden told reporters in response to a question.

It is for the first time he's publicly invoked the word genocide since Putin began his deadly assault on Ukraine on February 24.

Biden has previously accused Russia of committing war crimes in Ukraine.

The evidence is mounting. It's different than it was last week. More evidence is coming out of the -- literally, the horrible things that the Russians have done in Ukraine. We are going to only learn more and more about the devastation, Biden said.

And we'll let the lawyers decide internationally whether or not it qualifies, but it sure seems that way to me, he said.

In his Iowa address, Biden said that Putin's invasion of Ukraine has driven up gas prices and food prices all over the world.

"The two largest grain producers in the world, Ukraine and Russia, are not doing what they usually do, so everything is going up," he said.

Ukrainian President Volodymyr Zelenskyy has also accused Putin and Russia of committing genocide.

Taking to Twitter to react to Biden's genocide remarks, Zelenskyy 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."

The United Nations broadly defines genocide as seriously harming or killing members of a group with the intent to destroy, in whole or in part, a national, ethnical, racial or religious group.

National security adviser Jake Sullivan said last week that the US has "seen war crimes" but they "have not seen a level of systematic deprivation of life of the Ukrainian people to rise to the level of genocide."

The US has historically been reluctant to declare use the word genocide. It was just last month that the US used the word to refer to the widespread slaughter of civilians by military forces in Myanmar that began in 2016, the National Public Radio has said.