Washington, 18 July 2024 (dpa/MIA) — US President Joe Biden has tested positive for Covid-19 and is suffering mild symptoms, the White House said on Wednesday evening.

Biden is "vaccinated and boosted and he is experiencing mild symptoms," White House Press Secretary Karine Jean-Pierre said in a statement.

The positive test came as Biden, who is seeking re-election in November, was campaigning in Nevada.

He met with supporters at a Mexican restaurant in Las Vegas earlier on Wednesday but was forced to cancel a planned speech at a conference hosted by UnidosUS, a Latino civil rights organization.

Nevada is one of a small handful of so-called "swing states," meaning a state in which both Democrats and Republicans have a strong chance of winning.

Biden will be returning to his private residence in Delaware "where he will self-isolate and will continue to carry out all of his duties fully during that time," according to the White House.

"I am feeling good and thank everyone for the well wishes," Biden later said in a post on his official account on social media platform X.

Biden's doctor said the president had shown "upper respiratory symptoms" in the afternoon, including a runny nose and a cough.

The results of a PCR confirmation test are still pending but Biden has received the first dose of the Covid drug Paxlovid, according to the physician.

Biden, 81, last tested positive for Covid-19 two years ago. At the time, he only suffered from mild symptoms, according to the White House.

Due to his advanced age, the US president is considered to be at higher risk of becoming severely ill from Covid-19.

Wednesday's positive test is almost certain to fuel the current debate on Biden's health.

Following his disastrous debate performance against Republican rival Donald Trump last month, a number of Democrats have publicly called on Biden to step aside, voicing concerns he may not be fit enough to run for a second term.

Biden has so far been defiant, insisting that he will remain in the race and is capable of beating Trump.

Emerging evidence suggests that the risk of new-onset dementia after Covid in older adults (age 60+) — from a systematic review of 11 studies vs. controls — increases around 60 percent. After severe Covid, the risk increases 17 times, according to experts.