Kevin Hart has stepped down as the host of the 2019 Oscars less than two days after taking on the job for the first time.

The comedian was announced as the Academy Awards MC on Wednesday and now his dream is already over thanks to a series of resurfaced derogatory Twitter comments aimed at the gay and lesbian community, dating back to 2009.

His withdrawal announcement via Twitter on Thursday night came just hours after a defiant Hart took to Instagram to blast critics who were insisting he was the wrong man for the job.

Offering no apologies for his ill-advised past remarks, he urged his critics to "stop looking for reasons to be negative", adding, "Stop searching for reasons to be angry… I swear I wish you guys could see/feel/understand the mental place that I am in. I am truly happy people… there is nothing that you can do to change that… NOTHING."

He concluded his post by stating: "Please take your negative energy and put it into something constructive… I LOVE EVERYBODY… ONCE AGAIN EVERYBODY. If you choose to not believe me then that's on you… Have a beautiful day."

But hours later he apologised for his past tweets and withdrew as Oscars host.

"I have made the choice to step down from hosting this year's Oscars… this is because I do not want to be a distraction on a night that should be celebrated by so many amazing talented artists," the Jumanji: Welcome to the Jungle star wrote. "I sincerely apologize to the LGBTQ community for my insensitive words from my past.

"I'm sorry that I hurt people… I am evolving and want to continue to do so. My goal is to bring people together not tear us apart. Much love & appreciation to the Academy. I hope we can meet again."