Joe Biden accused President Trump of “pushing flat-out lies…against me and my family” in an op-ed late Saturday — and repeated his vow to beat the incumbent “like a drum” in the 2020 election.

The Democratic frontrunner pushed back against Trump’s claim that he improperly urged the ouster of Ukraine’s top prosecutor because he was investigating a local energy firm that employed his son Hunter Biden.

“President Trump seemingly cannot tell the truth — about anything. He slanders anyone he sees as a threat,” Biden wrote in The Washington Post.

“That is why he is frantically pushing flat-out lies, debunked conspiracy theories and smears against me and my family, no doubt hoping to undermine my candidacy for the presidency.”

Earlier on Saturday, Biden snapped at a reporter who asked if his son’s dealings in Ukraine posed a conflict of interest. It was the second time in two weeks that he berated a journalist for bringing up the entanglements.

“It’s not a conflict of interest,” Biden said. “There’s been no indication of any conflict of interest from Ukraine or anywhere else. Period.”

In his op-ed, Biden accused Trump of “abuse of power” for “directly asking three foreign governments to interfere in US elections,” meaning Russia, Ukraine and China.

“Every day… more and more evidence is uncovered revealing that President Trump is abusing the power of the presidency and is wholly unfit to be president,” Biden wrote.

“He is using the highest office in the land to advance his personal interests instead of the national interest.”

Biden appeared to be referring to Trump’s July 25 call, where he asked Ukrainian leader Volodymyr Zelensky to investigate the presidential candidate and his son.

He blasted people in the White House who “recognized just how profoundly wrong it was and worked overtime to cover up Trump’s abuse.”

Biden then applauded the “courage” of the whistleblower who came forward about the call, sparking House Speaker Nancy Pelosi to launch an impeachment inquiry.

Trump has defended the Zelensky call and his request that China investigate the Bidens over Hunter Biden’s business dealings in the two countries, saying he was simply trying to fight corruption.

But Biden accused Trump of being more focused on reelection than on the issues, including on gun safety legislation. He also criticized Trump for pulling out of the Paris climate agreement.

“A president who puts his self-interest ahead of the public good and the nation’s security poses a threat to the daily lives of every American,” Biden wrote.

Addressing Trump and “those who facilitate his abuses of power, and all the special interests funding his attacks against me,” Biden wrote: “Please know that I’m not going anywhere.”

“You won’t destroy me, and you won’t destroy my family,” he wrote. “And come November 2020, I intend to beat you like a drum.”