This week's brutal assassination of longtime conservative activist Charlie Kirk at an event in Utah has left many Americans in mourning.

One of them is Donald Trump Jr., who took to social media and lamented the devastating loss of his "little brother."

Trump calls Kirk "one of the most courageous, principled men I’ve ever known"

According to Breitbart, Trump made that declaration on Wednesday evening, writing, "Charlie wasn’t just a friend — he was like a little brother to me - and to millions of people around the world - he was a true inspiration."

This isn’t my strong suit and I don’t even know how to begin to put into words the loss I am feeling right now over the assassination of Charlie Kirk. Charlie wasn’t just a friend — he was like a little brother to me - and to millions of people around the world - he was a true…

— Donald Trump Jr. (@DonaldJTrumpJr) September 10, 2025

"He was one of the most courageous, principled men I’ve ever known, and he lived every day with purpose," the president's son recalled.

"His faith in God was unshakable, his love for Erika was inspiring, and the way he adored and cared for his two beautiful kids showed the kind of man he truly was," Trump stressed.

"We can’t wait to tell people how much they mean to us"

"This loss is absolutely devastating — not only for Erika and the kids, but for our country. We’ve lost a leader, a fighter, and a man whose character and conviction were rare. Too rare," Trump lamented.

"I’ll honor him by loving boldly, speaking truth without fear, and continuing his spirit of courage. His fight lives on in all of us who loved him," Trump continued.

Trump also made a point of expressing words of advice to his X followers, saying, "Moments like this remind us just how fragile life is."

"We can’t wait to tell people how much they mean to us — we can’t admire them in silence. Charlie knew he was loved, but I want to say it again: he was a brother to me, and I will carry that with me forever," Trump asserted.

President confirmed Kirk's death in a post to Truth Social

Meanwhile, Politico pointed out how it was President Donald Trump's father who initially confirmed Kirk's death in a Truth Social post.

"The Great, and even Legendary, Charlie Kirk, is dead," the president wrote not long after Kirk had been shot. "No one understood or had the Heart of the Youth in the United States of America better than Charlie."

"No one understood or had the Heart of the Youth in the United States of America better than Charlie," the commander in chief observed.

The elder Trump concluded by stating, "He was loved and admired by ALL, especially me, and now, he is no longer with us. Melania and my Sympathies go out to his beautiful wife Erika, and family. Charlie, we love you!"