President Donald Trump marked the 24th anniversary of September 11, 2001, on Thursday morning at a Pentagon ceremony.

Trump paid homage to the 2,977 terror victims killed at the World Trade Center, Pentagon, and in Pennsylvania that fateful day, and their families.

“In the quarter of a century since those acts of mass murder, 9/11 family members have felt the weight of missed birthdays and empty bedrooms, journals left unfinished and dreams left unfulfilled,” Trump said.

“To every member that still feels a void every day of your lives, the First Lady and I unite with you in sorrow. And today, as one nation, we renew our sacred vow that we will never forget September 11, 2001,” he added.

Trump shared the gut-wrenching phone calls some of the victims made to loved ones in their final moments. One call was between Tom McGinnis, who was stuck on the 92nd floor of the North Tower, and his wife, Iliana.

“There are people jumping from the floors above us. If we get out of here, it’ll be a total miracle. I love you, darling. Take care of Caitlin,” he told his wife, according to Trump.

Three moments later, the tower collapsed, Trump said.

Though the attacks were on some of the greatest symbols of America and its values, Trump said Americans’ response to the moment of tragedy demonstrates an undying resiliency.

“On that fateful day, savage monsters attacked the very symbols of our civilization,” he said. “Yet here in Virginia, in New York, and in the skies over Pennsylvania, Americans did not hesitate. They stood on their feet, and they showed the world that we will never yield, we will never bend, we will never give up, and our great American flag will never, ever fail.”

The observance event came a day after the horrific assassination of Turning Point USA founder Charlie Kirk rocked America. Trump announced at the top of his remarks that he will honor Kirk posthumously with the Presidential Medal of Freedom.