WASHINGTON (REUTERS) - US President Donald Trump on Saturday (July 4) vowed to defeat the "radical left" in an Independence Day speech at the White House that condemned recent protests against monuments of historical figures as attempts to destroy the United States.

Mr Trump claimed without evidence that 99 per cent of cases in the United States were "totally harmless." In fact, many US states marked a record number of new Covid-19 cases. In Texas alone, 7,890 patients were hospitalised after 238 new admissions over the past 24 hours.

While criticism mounted over his handling of the pandemic, Mr Trump said China must be "held accountable" for failing to contain the disease.

The administration held a fireworks display over the National Mall as night fell after Mr Trump's speech, despite Washington Mayor Muriel Bowser's warnings that the mass spectator event would defy health officials' guidance during the pandemic.

Just steps from where Mr Trump spoke, peaceful protesters marched down blocked-off streets around the White House, Black Lives Matter Plaza and the Lincoln Memorial. They were confronted by counter-protesters chanting, "USA! USA!" but there were no reports of violence.

Millions of Americans have been demonstrating against police brutality and racial inequality since the May killing of Mr George Floyd, a 46-year-old Black man who died after a white Minneapolis police officer knelt on his neck for nearly nine minutes.

In addition to achieving police reforms in some cities, some protesters have removed Confederate statues and other symbols of America's legacy of slavery.

"There have always been those who seek to lie about the past in order to gain power in the present, those that are lying about our history, those who want us to be ashamed of who we are," Mr Trump said on Saturday. "Their goal is demolition."

Mr Trump's Fourth of July remarks doubled down on a Friday night speech at Mount Rushmore in South Dakota, where he accused "angry mobs" of trying to erase history and used the speech to paint himself as a bulwark against left-wing extremism.

Just months before November's presidential election, opinion polls in key states show Mr Trump trailing his Democratic rival, former Vice-President Joe Biden.

Mr Biden wrote a Fourth of July opinion piece that struck a contrasting note with the Republican president and accused him of finding "new ways to tarnish and dismantle our democracy" every day.

In a separate letter to donors, Mr Biden said: "We have a chance now to give the marginalised, the demonised, the isolated, the oppressed, a full share of the American dream."

Mr Trump, in his Saturday speech, also said the US would have a vaccine or therapeutic solution to the virus "long before" the end of 2020.

Such a success could help the US economy and Mr Trump's chances of re-election.

On Thursday, a top US health official said he was optimistic the Trump administration's vaccine-acceleration programme "Operation Warp Speed" will generate a safe and effective vaccine for Covid-19 by year-end.

Saturday's speech at the White House was capped off by fighter jet air shows and a fireworks display over the National Mall.

Washington Mayor Muriel Bowser had tried to dissuade the Trump administration from holding the event because it went against health officials' guidance during the pandemic.

Apart from fireworks spectators, activists of different stripes also appeared willing to disregard the health warnings.

Roar of the Deplorables, a bikers group, said via social media that they planned to gather in Washington on Saturday to stand in protest against what they call "the anti-Trump regime"and to celebrate the nation's birthday.

Freedom Fighters DC, a new activist group which seeks to rally an ethnically diverse generation of supporters behind liberty for all people, especially the black population of Washington, is one of the anti-racism groups ignoring the mayor's heed to refrain from gathering.

"Black folks are not free from the chains of oppression, so we don't get to truly celebrate Independence Day," said Ms Kerrigan Williams, 22, one of the founders of the group, which will host a march and an arts demonstration on Saturday afternoon. "We're marching today to showcase that black folks are still fighting for the simple liberties that the Constitution is said to provide."