Republican US House Speaker Kevin McCarthy says he has directed House committees to launch an impeachment inquiry into President Joe Biden.
Republicans allege that when Biden was vice president, he exploited his position to illegally get involved in his son's business in Ukraine and elsewhere.
McCarthy told reporters on Tuesday that Republicans have "uncovered serious and credible allegations" into Biden's actions. He added, "These are allegations of abuse of power, obstruction and corruption."
He said that "these facts should concern all Americans," regardless of their party or who they voted for. He urged Biden to cooperate with the investigation.
Former President Donald Trump maintains a high support rate among Republicans ahead of the presidential election in the autumn of next year.
But Trump has been indicted four times, and calls for probes into allegations of corruption involving Biden have been mounting among conservative hardliners within the party.
A White House spokesperson said Republicans have turned up no evidence of wrongdoing, and called their latest move "extreme politics at its worst."