US President Donald Trump’s personal lawyer, Rudy Giuliani, has tested positive for the coronavirus, Mr Trump has posted on Twitter.

“Rudy Giuliani, by far the greatest mayor in the history of NYC, and who has been working tirelessly exposing the most corrupt election (by far!) in the history of the USA, has tested positive for the China virus,” Mr Trump said.

He commonly calls COVID-19 the “China virus” – a term that has drawn backlash.

Mr Giuliani, 76, later confirmed the diagnosis in a tweet of his own.

“I’m getting great care and feeling good,” he wrote.

“Recovering quickly and keeping up with everything.”

US media is reporting Mr Giuliani was admitted to MedStar Georgetown University Hospital in Washington on Sunday (local time). One source told The Associated Press that he was showing symptoms of the virus.

Tweet from @RudyGiuliani

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Mr Giuliani is the latest in a string of Trump officials and White House staff – including Mr Trump himself, his wife Melania and son Barron – to have contracted the deadly virus. Mr Giuliani’s son Andrew, who is White House aide, tested positive for COVID a fortnight ago.

The former New York mayor has been spearheading Mr Trump’s floundering effort to overturn his November 3 election loss to Democratic President-elect Joe Biden through a flurry of lawsuits.

Mr Trump and Mr Giuliani have repeatedly claimed, contrary to evidence, that the election outcome was marred by widespread fraud.

Mr Giuliani visited Georgia on Thursday, where he urged state politicians to stop certification of Mr Biden’s win. He made similar pleas in Michigan on Wednesday.

In Arizona last Monday, Mr Giuliani spent almost 10 hours with Republican politicians at a Phoenix hotel. He appeared without a mask, and at one point even asked a fellow witness to remove her mask while he was sitting less than two metres away.

Arizona’s state legislature said after news of Mr Giuliani’s positive diagnosis emerged that it would shut down its house and its senate this week amid fears about the spread of the virus.

Mr Trump’s campaign released a statement from his legal team on Sunday night saying Mr Giuliani had tested negative just before he travelled to Arizona, Michigan and Georgia.

“The mayor did not experience any symptoms or test positive for COVID-19 until more than 48 hours after his return,” it said.

Mr Giuliani also appeared on Fox News just hours before Mr Trump’s tweet of the virus diagnosis. Fox News said he “appeared well” at the time, and he was not present in the studio for the interview.

Mr Trump and many of his close associates have baulked at advice to wear masks and avoid crowds to stem transmission of the coronavirus, which has roared to record levels in the US.

-with AAP