Rep. Marjorie Taylor Greene claimed Biden wants to defend Ukraine because of his son, Hunter.
In an interview on Steve Bannon's "War Room", she claimed Ukraine has "dirt" on Hunter Biden.
Biden, alongside NATO allies, have pledged defense to Ukraine in case of a Russian attack.
Rep. Marjorie Taylor Greene claimed Tuesday that President Joe Biden was backing Ukraine against Russia because Ukraine "has dirt on Hunter Biden."
In an interview on Steve Bannon's "War Room" podcast, Greene said Biden has been "playing cover" for his son Hunter, who has been at the center of baseless allegations of corruption over his business dealings with Ukraine.
Greene told Bannon: "I am blown away with what we're seeing. The president of the United States Joe Biden is willing to take our military to war ... against nuclear Russia because of Ukraine."
"You cannot deny this, it's because Ukraine has the dirt on Hunter Biden. Ukraine has the dirt on Joe Biden, our president," she said, without giving further specifics. "This is why we can have many of our troops get killed in this war that Joe Biden wants to have happened."
Biden has never threatened to go to war with Russia amid the growing military tensions with Ukraine. The US has, however, joined countries like Ukraine and the UK in warning of a Russian invasion, and called for a deescalation.
Watch Greene's interview here.
Russia has in recent weeks placed tens of thousands of troops and weaponry at Ukraine's border, but repeatedly denies plans to invade the country.
Earlier this week the Pentagon said the US was placing 8,500 troops on "heightened alert" so they are prepared to respond to an invasion. No final decisions to deploy US forces have been made, however.
Last month Biden threatened to impose heavy sanctions on Russia if it invaded Ukraine, and on Tuesday, said he would consider slapping Russian President Vladimir Putin with personal sanctions.
Biden also said that a Russia attack would be the "largest invasion since World War II."