A newly minted graduate of Marjory Stoneman Douglas High School in Parkland, Florida, said Monday that Harvard University had rescinded its admission offer over racist and offensive remarks he made as a 16-year-old that were recently posted on Twitter.

Kyle Kashuv, 18, a survivor of the deadly shooting that killed 17 people last year who became a gun rights activist, announced Harvard’s decision on Twitter, posting purported letters he received from the college.

Kashuv apologized on Twitter on May 22 after screenshots circulated online of racist remarks he made in a Google Doc and in text messages a couple of years ago. Kashuv used the N-word multiple times in a shared document and study guide used for an Advanced Placement U.S. history exam, as first reported by HuffPost.

On Monday, Kashuv said that he submitted a written apology to Harvard after the school contacted him May 24 asking him to explain the comments. He said the college then informed him that it would no longer accept him, citing its serious consideration of “the qualities of maturity and moral character.”

“After careful consideration the committee voted to rescind your admission to Harvard College,” William R. Fitzsimmons, dean of admissions and financial aid, wrote Kashuv, according to a copy of the letter dated June 3 that Kashuv posted on Twitter. “We are sorry about the circumstances that have led us to withdraw your admission, and we wish you success in your future academic endeavors and beyond.”

Kashuv said his request to meet with the admissions committee to discuss the matter in person was denied.

"Harvard deciding that someone can’t grow, especially after a life-altering event like the shooting, is deeply concerning," Kashuv wrote on Twitter. He says he's still exploring his options for college following the rejection.

A Harvard spokeswoman told NBC News on Monday it "does not comment publicly on the admissions status of individual applicants."

According to its admission policies, Harvard reserves the right to withdraw an offer of admission for a number of reasons, including, "if an admitted student engages or has engaged in behavior that brings into question their honesty, maturity or moral character."

Kashuv distinguished himself from other Parkland survivors as a gun rights advocate and served as the high school outreach director for conservative group Turning Point USA.

In 2017, Harvard rescinded admission offers for at least 10 applicants who had shared sexually explicit and other offensive memes and messages in a private Facebook group.