(Reuters) - Americans are paying the price for President Donald Trump’s failure to hold China to account over the coronavirus pandemic, presumed Democratic presidential nominee Joe Biden said on Friday, as the two campaigns spar over who can better confront challenges posed by Beijing.

FILE PHOTO: Democratic U.S. presidential candidate and former Vice President Joe Biden speaks during the 11th Democratic candidates debate of the 2020 U.S. presidential campaign, held in CNN's Washington studios without an audience because of the global coronavirus pandemic, in Washington, U.S., March 15, 2020. REUTERS/Kevin Lamarque/File Photo

Trump’s campaign has moved swiftly to mine Biden’s nearly five-decade record as a senator, vice president and presidential candidate for fodder for attacks related to China, an issue that has emerged as a major battlefield for the campaigns ahead of November’s election.

A pro-Trump political action committee, America First Action, on Thursday unveiled $10 million in new attack ads against Biden in the battleground states Pennsylvania, Michigan and Wisconsin, casting the former vice president as friendly to China’s ruling Communist Party, while highlighting Trump’s decision in January to ban travel from the country after the coronavirus outbreak started there.

Biden’s allies have welcomed the fight, arguing that Trump undermined U.S. disease control protections and allowed the rapid spread of the novel coronavirus that first emerged in China but has now killed more than 35,000 people in the United States, more than in any other country.

“The uncomfortable truth is that Donald Trump left America exposed and vulnerable to this pandemic. He ignored the warnings of health experts and intelligence agencies and put his trust in China’s leaders instead,” Biden said in a video ad posted online.

Biden said Trump ended funding for a program created under the Obama-Biden administration to track emergency infectious diseases, cut Centers of Disease Control and Prevention experts in China by two thirds, and left empty a slot for an American official within China’s disease control agency.

“And now, we’re all paying the price,” he said.

Democratic political group American Bridge 21st Century Foundation unveiled the “first wave” of a $15 million anti-Trump advertising campaign on Friday, rolling out ads also in Pennsylvania, Michigan and Wisconsin.

The ads criticized Trump for his delivery of U.S. medical supplies to help China and for praising Chinese President Xi Jinping for transparency in handling the virus despite widespread skepticism about the accuracy of China’s reported death toll, which now stands at about 4,600, following a revision on Friday that added nearly 1,300 people to the toll.

“Trump trusted China, sent China our supplies, and just look at the mess we’re in now,” it said.

The Trump group also established a “Beijing Biden” website dedicated to fundraising and to chronicling Biden’s past statements as “naive” on the threats posed by the world’s second largest economy.

Trump’s campaign responded to Biden’s video with its own, condemning the former vice president for objecting to Trump’s late-January order restricting non-U.S. travelers from China to combat COVID-19.

“FLAT OUT DICTATORS”

As the coronavirus spread, Biden appears to have hardened his tone toward China, comparing its leaders to “Jack the Ripper” in a March Democratic debate with presidential rival Senator Bernie Sanders, who has since dropped his White House bid and endorsed Biden.

“These are flat out dictators. Period. And they should be called for it, straight up,” Biden said at the time.

Still, Biden may have to overcome a legacy of criticism – some from former senior Obama administration officials – that they were soft on Beijing, especially in not responding forcefully to China’s militarization of man-made islands in contested waters of the South China Sea.

Biden is actively considering people who would fill key posts, including those related to China and foreign policy, if he is elected president.

He told donors at a fundraiser Thursday night that there are hundreds of former officials with experience in the Defense Department and State Department, “including some Republicans” whom he would considering bringing back.