In a tweet, Christie said he checked himself into Morristown Medical Center in consultation with his doctors.
"While I am feeling good and only have mild symptoms, due to my history of asthma we decided this is an important precautionary measure," he said in the tweet.
[Ads /]
Christie, who is also an ABC News political contributor and was part of the news broadcast's debate coverage, shared his positive diagnosis on Saturday morning.
"I just received word that I am positive for COVID-19," Christie said on Twitter Saturday morning.
RELATED: Notable figures who've recently said they have COVID-19
Trump says he and first lady tested positive for coronavirus
Following Christie's announcement, New Jersey Gov. Phil Murphy issued a statement wishing him a speedy recovery.
"Tammy and I continue to keep Governor Christie in our thoughts and prayers. We all know he is a fighter and wish him a full and speedy recovery," the statement said.
Christie is among those to take part in Trump's debate preparations and now have tested positive for COVID-19.
[Ads /]
As of now, five out of nine known participants have tested positive: President Donald Trump, campaign manager Bill Stepien, former senior adviser Kellyanne Conway, and counselor Hope Hicks.
"I want to thank all of my friends and colleagues who have reached out to ask how I was feeling in the last day or two," Christie said.
Christie said he will be keeping the "necessary folks apprised" of his condition.