President Donald Trump, at a memorial event at the Pentagon on Thursday on the anniversary of the 9/11 terror attacks, announced he will posthumously award Charlie Kirk the Presidential Medal of Freedom.

Kirk, a prominent conservative activist, was shot during an event at Utah Valley University on Wednesday. Trump later that day announced his death.

"Charlie was a giant of his generation, a champion of liberty and an inspiration to millions and millions of people," Trump said on Thursday.

"We miss him greatly, yet I have no doubt that Charlie's voice and courage put into the hearts of countless people, especially young people, will live on," the president continued.

The Presidential Medal of Freedom is the highest civilian award in the U.S. Trump said that the day of that ceremony would be announced soon, adding he thought it would surely draw a big crowd.

A manhunt for Kirk's killer is underway. The FBI said on Thursday it has recovered what is believed to be the weapon used by the shooter, and officials said the suspect is believed to be a college-aged individual.

This is a developing story. Please check back for updates.