President Donald Trump and former Vice President Joe Biden battled over the government's coronavirus response on Thursday.

Biden said on Thursday that the administration's "failure on testing is colossal, and it's a failure of leadership, planning and execution."

Tim Murtaugh, the Trump campaign's communications director, attacked Biden's record and his campaign's messaging on the coronavirus in an email to supporters on Thursday.

Murtaugh accused Biden's campaign of spreading a conspiracy theory that Trump deliberately encouraged the virus' spread, interpreting a tweet by Biden digital director Bob Flaherty as evidence.

Biden himself has not claimed that Trump allowed the coronavirus to spread on purpose.

Visit Business Insider's homepage for more stories.

President Donald Trump and former Vice President Joe Biden battled over the government's coronavirus response on Thursday, and the Trump campaign accused Biden's team of spreading conspiracies.

After Biden delivered a speech on Thursday condemning the administration's slow and chaotic response to the pandemic, Tim Murtaugh, the Trump campaign's communications director, attacked Biden's record and his campaign's messaging on the coronavirus in an email to supporters.

"In the past, Joe Biden has shown terrible judgment and incompetence in the face of public health issues," Murtaugh wrote. "[Trump's] every move has been aimed at keeping Americans safe, while Joe Biden has sought to capitalize politically and stoke citizens' fears."

Murtaugh also accused Biden's campaign of spreading a conspiracy theory that Trump deliberately encouraged the virus' spread, interpreting a tweet by Biden digital director Bob Flaherty as evidence. Flaherty tweeted, "Sure seems like this is getting out of hand and Donald Trump decided to let it be this way."

"Yesterday his campaign actually raised the vile conspiracy theory that the President purposely allowed the coronavirus to spread," Murtaugh wrote. In a tweet, Murtaugh linked to a Breitbart article about Flaherty's tweet.

It's unclear what exactly Flaherty meant by his message, but Biden's rapid response director Andrew Bates replied to Murtough on Twitter, "Get a grip. And focus on containing the virus instead of containing the truth."

The Trump campaign did not immediately respond to a request for comment.

Biden himself has not claimed that Trump allowed the coronavirus to spread on purpose. Rather, he has repeatedly criticized the administration's response, including in an interview with MSNBC's Lawrence O'Donnell on Monday as well as his Thursday afternoon speech from Delaware where he laid out his plan to halt the spread of coronavirus.

Biden said on Thursday that the administration's "failure on testing is colossal, and it's a failure of leadership, planning and execution."

"We will lead by science," he went on. "Downplaying it, being overly dismissive, or spreading misinformation is only going to hurt us and further advantage the spread of the disease."

Both the Biden and Trump campaigns declined to comment on the record for this story.

A host of Democrats and journalists have criticized Trump for attempting to downplay the threat posed by the coronavirus. Among the misleading statements Trump has made is his repeated attempt to compare the coronavirus to the seasonal flu, even though his own top public health expert, Dr. Anthony Fauci of the National Institutes of Health, told Congress the virus' mortality rate is at least 10 times that of the flu.

Last month, Trump told supporters the coronavirus was a "hoax" cooked up by Democrats to hurt him politically.

As some Republicans insist on referring to the coronavirus as "Chinese," prompting accusations of racism, Biden also said that leaders should not "fall back on xenophobia."

"Labeling COVID-19 a foreign virus does not displace accountability for the misjudgments that have been taken thus far by the Trump administration," Biden said.