Chris Christie in hospital after being diagnosed with Covid-19

The former New Jersey governor, a close ally of the president, is one of many Republicans to tested positive after attending a White House Rose Garden event last weekend.

WASHINGTON — Former New Jersey Gov. Chris Christie announced Saturday that he was in a hospital after having tested positive for the coronavirus earlier in the day.

"In consultation with my doctors, I checked myself into Morristown Medical Center this afternoon. While I am feeling good and only have mild symptoms, due to my history of asthma we decided this is an important precautionary measure," Christie wrote on Twitter. "I am thankful for our hardworking medical professionals and look forward to coming home soon."

He tweeted earlier Saturday that he had "just received word" that he was positive and would be "receiving medical attention."

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Christie, a close ally of President Donald Trump, is one of a growing number of Republicans who have been diagnosed with the coronavirus after having attended a Rose Garden ceremony Sept. 26 in honor of Trump's Supreme Court nominee, federal appeals Judge Amy Coney Barrett.

Although the Rose Garden event was outdoors, very few attendees wore masks, and there was no effort to observe social distancing. Some attendees also participated in other celebratory events honoring Barrett, which took place inside.

In addition to the president and first lady Melania Trump, former top Trump aide Kellyanne Conway, Republican Sens. Thom Tillis of North Carolina and Mike Lee of Utah, University of Notre Dame President John Jenkins and a White House journalist have all tested positive since they attended the Rose Garden ceremony.

Christie was part of Trump's debate preparation team ahead of the first matchup against Democratic nominee Joe Biden on Tuesday. He said Friday on ABC's "Good Morning America" that "no one was wearing masks in the room during that time when we were prepping the president."

"The group was about five or six people in total," he said.

Christie attended a White House news conference on Sept. 27, sitting in the briefing room near administration officials and reporters without a mask.