"To preserve our Constitution, our democracy, our basic integrity, he should be impeached," Biden said of the President, speaking at a town hall in New Hampshire.
"He's shooting holes in the Constitution," Biden said. "And we cannot let him get away with it."
Biden said Trump "has indicted himself by obstructing justice, refusing to comply with the congressional inquiry, he's already convicted himself. In full view of the world and the American people, Donald Trump has violated his oath of office, betrayed this nation and committed impeachable acts."
"Trump will do anything to get re-elected, including violating the most basic forms of democracy. It's stunning, and it's dangerous," Biden said. He added, "No president in history has dared to engage in such unimaginable behavior."
It was Biden's most forceful response yet to Trump's efforts to pressure Ukraine , and then publicly ask China, to investigate Biden and his son, Hunter Biden -- even though there is no evidence of wrongdoing on the part of either Biden. Biden said Trump is pushing "lies and distortions and smears -- that's all they are."
Biden had been more cautious than his Democratic competitors to call for impeachment. Massachusetts Sen. Elizabeth Warren, who is neck-and-neck with Biden in recent polls, called for an impeachment inquiry into Trump in April , after former special counsel Robert Mueller delivered his report on Russian interference in the 2016 presidential election.
"He's just flat doing what he's always done: Lying," Biden said. "And he's spending tens of millions of dollars this early in the campaign during the Democratic primary to spread lies. He's trying to orchestrate a campaign where truth and the facts are irrelevant."
"His lying is matched only by his manifest incompetence," Biden added.
Trump tweeted in response that Biden's call was "pathetic."
"I did nothing wrong," Trump wrote.
Biden said in his speech that Trump would "stop at nothing to save himself" from losing his re-election bid in 2020 and said Trump is "afraid of just how badly I will beat him next November." He said Trump "started with me and my family" and would attack any opponent necessary.
"This isn't a game. It's deadly serious. The United States cannot afford to have a president who will abuse whatever power is available to him to get re-elected. That's what it's all about," Biden said. "And here's the kicker: The people around the President knew that what he was doing was wrong -- profoundly wrong. So what did they try to do? They tried to cover it up by hiding the evidence."
Biden praised the whistleblower who flagged Trump's call with the Ukrainian president to the intelligence community's inspector general, and lambasted Trump for attacking the whistleblower.
"Trump's scheme has been exposed," Biden said.