Joe Biden says Congress must use its “full constitutional authority” to determine whether President Donald Trump asked the Ukrainian president for dirt on Biden as he runs for the Democratic presidential nomination.

Biden says if Trump doesn’t comply on that and other inquiries, he “will leave Congress … with no choice but to initiate impeachment.”

Biden says that would be a tragedy of Trump’s “own making.”

He adds that President Trump apparently believes he is “above the law.”

The former vice president spoke Tuesday in Delaware.