Donald Trump has celebrated independence day with a string of false and misleading claims attempting to play down the coronavirus pandemic and warning that China will be “held accountable”.

The US president staged a “Salute to America” jamboree on the south lawn of the White House with flyovers by military jets, parachute jumps and patriotic songs, but little effort among guests to physical distance or wear face masks.

The country has undergone staggering changes unthinkable when Trump hosted the first such event a year ago on 4 July with tanks and other military hardware at the Lincoln Memorial. The coronavirus has infected 2.8m Americans and killed nearly 130,000, the worst tallies in the world.

Saturday’s national celebration was inevitably more subdued, but the president refused to let the pandemic or dismal poll figures rain on his parade, waving with his wife, Melania, from a White House balcony then walking the south lawn to ripples of applause and a cry of: “Four more years!”

“We got hit by the virus that came from China,” the president said, prompting a strange whoop and applause from someone in the audience. “We’ve made a lot of progress. Our strategy is moving along well. It goes out in one area, it rears back its ugly face in another area. But we’ve learned a lot. We’ve learned how to put out the flame.”

The number of infections now regularly tops 50,000 per day, higher than in April when the US was in the first grip of infections. Dr Anthony Fauci, the nation’s top infectious diseases expert, warned this week: “I think it’s pretty obvious that we are not going in the right direction.”

Trump returned to his now familiar and baseless complaint that America has a high caseload because it performs more tests. “Now we have tested almost 40m people. By so doing, we show cases, 99% of which are totally harmless. Results that no other country can show because no other country has the testing that we have, not in terms of the numbers or in terms of quality.”

It was unclear how the president arrived at the “99%” harmless figure.

He also returned to his criticisms of the source of the coronavirus. “China’s secrecy, deceptions and cover up allowed it to spread all over the world. One hundred and eighty-nine countries and China must be held fully accountable.”

There was applause from the guests, but the White House has so far failed to detail what measures it is considering against Beijing, with which it recently struck a major trade deal.

And contradicting Fauci and other public health experts, the president offered a wildly optimistic prediction: “We’ll likely have a therapeutic and/or vaccine solution long before the end of the year.” The presidential election is on 3 November.

But the lion’s share of Trump’s remarks were a rehashing of a speech he gave on Friday night at Mount Rushmore, breaking from 4 July tradition by seeking to stoke a culture war and pour salt on America’s racial wounds instead of a unifying message.

“We are now in the process of defeating the radical left, the Marxists, the anarchists, the agitators, the looters, and people who in many instances have absolutely no clue what they are doing,” he said.

“We will never allow an angry mob to tear down our statues, erase our history, indoctrinate our children or trample on our freedoms … We will teach our children to cherish and adore our country so they can build its future. Together, we will fight for the American dream.”

Trump pointedly said “our way of life” began in 1492 “when Columbus discovered America”. Statues of Christopher Columbus have been toppled along with those of Confederate generals during several weeks of protest against racial injustice following the police killing of George Floyd, an African American man, in Minneapolis.

Some have argued that, instead of America’s familiar birthday in 1776, the nation truly began in 1619 with arrival of the first enslaved Africans in Virginia.

But Trump went on: “In every age, there have always been those who lie about the past in order to gain power in the present … Their goal is demolition. Our goal is not to destroy the greatest structure on earth, what we have built, the United States of America.”

Trump touted an executive order he issued on Friday for the creation of a national garden of Americans heroes and berated the media for dishonouring, lying and slandering the country’s best. He added: “We will not throw away our heroes. We will honour them and we will prove worthy of their sacrifice … The patriots who built our country were not villains. They were heroes.”

Following his speech, Trump and the first lady watched a spectacular display of military jets that have taken part in America’s military conflicts from the second world war onwards.