Former New York City mayor and current lawyer for the president has tested positive for the coronavirus, Donald Trump tweeted Sunday afternoon.

The president referred to Rudy Giuliani in his tweet as "by far the greatest mayor in the history of NYC," adding well wishes to his personal attorney.

Giuliani's son, Andrew, a special assistant to the president who tested positive for the virus back on Nov. 20, tweeted that his father was "resting, getting great care and feeling well."

Trump himself did not elaborate on any specifics of Giuliani's condition or whether the 76-year-old was experiencing symptoms related to the virus.

Giuliani did not immediately respond to a request for comment from NBC News. He wrote on Twitter late Sunday saying he's "getting great care and feeling good."

Giuliani traveled on Monday to Phoenix where he met with Republican legislators for an hourslong hearing in which he was maskless. The Arizona Republican Party tweeted a photo of Giuliani and several state GOP lawmakers standing shoulder-to-shoulder and maskless. The Arizona legislature announced Sunday, after Giuliani's diagnosis became public, that it would close for a week out of an abundance of caution "for recent cases and concerns relating to COVID-19.”

Giuliani also appeared maskless at a Nov. 25 hearing in Pennsylvania. And he did not quarantine after being near an infected person at a Nov. 19 news conference at the Republican National Committee’s headquarters. His son Andrew Giuliani, who is a White House aide, announced a day after the event that he had tested positive for the virus.

In a statement about the timeline of Giuliani's diagnosis, the Trump campaign said Giuliani tested negative twice immediately preceding his trip to Arizona, Michigan, and Georgia. Other members who had close contact with the former mayor will be self-isolating and getting tested.

Giuliani did not experience any symptoms before testing positive more than 48 hours after his return, according to the campaign's legal team. He was exhibiting some symptoms and was admitted Sunday to Georgetown University Medical Center in Washington, a person familiar with the matter who was not authorized to speak publicly told The Associated Press.

Giuliani is the latest person in the president's inner circle to contract COVID-19. CNBC reports at least 52 people connected to the White House have tested positive in recent months, including Trump, his chief of staff and several senior advisors.

Since the election, Giuliani has led the Trump campaign's so far unsuccessful attempt to overturn election results in a number of states.

Giuliani has continued to push unverified claims of voter fraud, appearing publicly for weeks without wearing a mask amid the ongoing coronavirus pandemic. As recently as last Thursday, Giuliani appeared maskless at a meeting with Georgia lawmakers.