Washington(CNN) Former Vice President Joe Biden on Wednesday for the first time called for President Donald Trump's impeachment.

"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.

In late September, Biden made his call for an impeachment inquiry conditional, and said if Trump did not cooperate with Congress, he would leave lawmakers with "no choice" but to start impeachment proceedings. Later that same day, House Speaker Nancy Pelosi announced a formal impeachment inquiry into Trump. Pelosi's call came after Trump admitted to discussing Biden and his son, Hunter, in his phone call with Ukrainian President Volodymyr Zelensky, and after dozens of House Democrats -- many from moderate or Trump-won districts -- announced their support for an inquiry.

In the two weeks since then, the White House has refused to comply with House Democrats' document, deposition and subpoena requests. Multiple Democratic members and aides over the past several days have told CNN that this stonewalling by the White House could end up bolstering their case for impeachment, and embolden Democrats' charges that the President is obstructing proceedings.

"He's just flat doing what he's always done: Lying," Biden said during his speech.. "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 responded on Twitter, "Stop stonewalling the Congress. Honor your oath. Respect the Constitution."

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.

With the impeachment proceedings underway, Trump has made several false claims in recent weeks about the Bidens. The President has repeatedly claimed Biden had called for the firing of a Ukrainian prosecutor who was "investigating his son." There is no evidence Hunter Biden was ever under investigation. The President has also claimed that "Joe Biden and his son walk(ed) away with millions of dollars from Ukraine and then millions of dollars from China." There is no basis for that claim.

The President has also claimed Biden pressured Ukraine to take chief prosecutor Viktor Shokin "off the case." Biden pressured Ukrainian leaders to fire Shokin -- the Obama administration, US allies and Ukrainian anti-corruption activists saw Shokin as unwilling to prosecute elite corruption -- but there is no public evidence that Biden sought to get Shokin removed from any particular case.

In addition, CNN's KFile reported a February 2016 bipartisan letter signed by several Republican senators that urged then-Ukrainian President Petro Poroshenko to "press ahead with urgent reforms to the Prosecutor General's office and judiciary." The Republican senators in the letter echoed calls then-Vice President Joe Biden made at the time.

The White House sent a blistering letter to House leaders on Tuesday that said the Trump administration would not cooperate with the impeachment inquiry. Trump's lawyers called the inquiry an illegitimate and unconstitutional effort to overturn the results of the 2016 election.