President-elect Joe Biden's pick for chief of staff Ron Klain previously decried a "fear epidemic" at the beginning of the COVID-19 outbreak, and praised New York City Mayor Bill de Blasio for participating in a large dinner in Queens.

"We don’t have a #COVIDー19 epidemic in the US but we are starting to see a fear epidemic," Klain said in a tweet dated Feb. 13. "Kudos to @NYCMayor (and others) for standing against that."

De Blasio had tweeted photos of the event, including one in which he's surrounded by nearly a dozen people at a table. "Our Chinatowns are open for business — make some dinner plans, do some shopping and stand with our neighbors!" he said.

RONALD KLAIN, BIDEN'S NEW CHIEF OF STAFF, RAISES EYEBROWS WITH 2014 TWEET SAYING ELECTIONS ARE 'RIGGED'

Klain, who served as former President Obama's ebola czar, has been critical of President Trump's response to the pandemic. More than a month after that tweet, the Biden campaign posted a video of Klain attacking President Trump for not acting "quickly" like other countries after the virus started spreading in January. 

"What did President Trump do? He downplayed it," Klain said. The video then showed what appeared to be a Feb. 27 clip of Trump claiming that the virus would disappear. 

"From the very beginning, Donald Trump had a 'Don't test, don't tell' mindset," he said, citing Trump's decision to disband a National Security Council pandemic response team in 2018.

In January, Klain similarly penned a Washington Post op-ed in which he cautioned against public officials making decisions out of fear -- specifically attacking the president's proposed ban on travel from China. 

FLASHBACK: BIDEN'S CHIEF OF STAFF PICK ADMITS OBAMA DID EVERYTHING WRONG WITH H1N1

"The first victim of an infectious disease outbreak is often rational decision-making; fear can spread even faster than disease in an era where social media can transmit misinformation in a manner not ironically called 'going viral,'" wrote he and Nicole Lurie, a former Health and Human Services official under Obama.  

"Xenophobia is a particular risk; it’s unjustified when Americans returning home from a foreign trip are just as likely to carry a disease with them as immigrants or foreign tourists. Our government is filled with the best scientists, medical professionals and researchers in the world. Their expertise — not fear or politics — should guide critical decisions."

In that op-ed, Klain and Lurie also criticize Trump for saying he had the coronavirus "under control." They went on to propose congressional funding for epidemic response, and better "leadership" from the White House.

The Biden campaign has also attacked Trump, citing his Feb. 3 interview with veteran journalist Bob Woodward. In it, Trump said that he wanted to downplay the virus' threat in order to avoid panicking the American people. Meanwhile, Trump has used Klain's own words to accuse the Obama-Biden administration of bungling its response to the swine flu. 

"Biden was a pathetic laughing stock all over Washington for the horrible way he handled the H1N1 Swine Flu. Even his own Chief of Staff said he didn’t know what he was doing!" Trump tweeted just before the election.

Klain responded: "I’m that guy. And if Donald Trump really cares about what I think, here you go: no President has bungled anything, ever, as badly as Trump has bungled COVID. Period."

Trump was apparently referring to Klain's comments at the Pandemic and Biosecurity Policy Summit hosted in May, 2019. 

At the time, he said “a bunch of really talented” people were working on it, but “did every possible thing wrong.”

CLICK HERE TO GET THE FOX NEWS APP

“Sixty million Americans got H1N1 in that period of time and it’s just purely a fortuity that this isn’t one of the great mass casualty events in American history,” Klain said. “It had nothing to do with us doing anything right, it just had to do with luck.”

The Biden transition team did not immediately respond to Fox News' request for comment.

Fox News' Brittany De Lea contributed to this report.