SANFORD (Florida) • United States President Donald Trump returned to the campaign trail on Monday for the first time since he announced his Covid-19 diagnosis, touting his management of the pandemic as opinion polls showed him losing more ground to Democratic rival Joe Biden.

Mr Trump arrived at the outdoor rally in Sanford, Florida, the first of six planned for this week, without a protective mask.

He tossed out masks to thousands of supporters standing shoulder to shoulder, most without protective face coverings, and repeatedly talked about his recovery from the coronavirus.

"I went through it now. They say I'm immune. I feel so powerful," Mr Trump told the crowd during his hour-long remarks.

"I will kiss everyone in that audience, I will kiss the guys and the beautiful women, I will give you a big fat kiss."

Mr Trump's return to his signature campaign rallies kicked off a three-week sprint to the Nov 3 election.

He was expected to travel to Pennsylvania yesterday night, visit Iowa today and go to North Carolina for an event tomorrow afternoon.

The Republican President, 74, is seeking to change the dynamics of a race that national opinion polls and some key state polls show he is losing to Mr Biden, 77.

The airport rally in Sanford indicated that Mr Trump had not reshaped his campaign approach or outlook since contracting the coronavirus, which has infected more than 7.8 million people in the US, killed more than 214,000 and put millions out of work.

He told supporters that coronavirus safety lockdowns had done great damage to the economy and were too drastic. "It's risky, but you gotta get out," he told supporters, who chanted: "We love you."

Critics have faulted Mr Trump for failing to encourage supporters at campaign events, and White House staff, to wear masks and abide by social-distancing guidelines.

At least 11 close Trump aides have tested positive for the virus.

Top US infectious disease expert Anthony Fauci told CNN that Mr Trump's planned campaign rallies this week threaten to advance the spread of the coronavirus.

"Look at it purely in the context of public health," Dr Fauci said.

"We know that that is asking for trouble when you do that. We've seen that when you have situations of congregant settings where there are a lot of people without masks, the data speak for themselves."

Asked about Dr Fauci's remarks about the rallies, Ms Courtney Parella, a Trump campaign representative, said, "We take strong precautions for our campaign events. Every attendee has their temperature checked, is provided a mask they're instructed to wear, and has access to plenty of hand sanitiser. We also have signs at our events instructing attendees to wear their masks."

Mr Trump's Florida rally came hours after the White House said he had tested negative for Covid-19 on consecutive days and was not infectious to others.

They were the President's first negative Covid-19 tests announced by the White House since Mr Trump said on Oct 2 that he had contracted the virus.

In a memo, White House doctor Sean Conley did not say when the tests were conducted but that they and other clinical and laboratory data "indicate a lack of detectable viral replication".

On Sunday, Mr Trump's assertion that he was now immune to the virus, made without evidence, drew a flag from Twitter for violating the social media platform's rules about misleading information related to Covid-19.

Scientific research has been inconclusive on how long people who have recovered from Covid-19 have antibodies and are protected from a second infection.

Mr Trump has worked furiously for months to shift public attention away from the virus and his handling of the pandemic.

But his own illness has put the spotlight squarely on his coronavirus response during the closing stretch of the race, with Mr Biden scaling up his attacks and reaching into states that normally lean Republican.

On Monday, Mr Biden made two campaign appearances in Ohio, where he was once considered a long shot but polls now show a tight race. Speaking in Cincinnati, he criticised Mr Trump for playing down the coronavirus threat and mocked the President's statements that he did not want to panic Americans.

"Trump is the one who panicked. His reckless personal conduct since his diagnosis, as well, has been unconscionable. And the longer Donald Trump is president, the more reckless he gets," Mr Biden said.

REUTERS, BLOOMBERG