Former President Trump said that spending time with Queen Elizabeth II was one of the most "extraordinary honors of my life" and called her "indispensable."
Trump made the statement in an op-ed for the Daily Mail published on Saturday.
The op-ed comes after Queen Elizabeth II died at Balmoral Castle in Scotland on Thursday at the age of 96.
"The times we spent with the Queen at Buckingham Palace and Windsor Castle are memories Melania and I will cherish for the rest of our lives," Trump said.
Trump met Queen Elizabeth II in July 2018 at Windsor Castle with first lady Melania Trump and met again in June 2019 at Buckingham Palace.
He wrote in the op-ed that few people in history "have more fully exemplified the traits of dignity, steadfastness, resolve, duty, and patriotic devotion."
Even as Queen Elizabeth II saw the United Kingdom, as Trump states, through multiple challenges such as the Cold War, the Blitz of London, Brexit, COVID, and more, "she was always there for her people."
"In the face of all adversity, she embodied the uniquely British attribute of a firm and quiet resolve," Trump said. "The qualities that served Queen Elizabeth so well as monarch also endeared her to the hearts of countless people all over the world."
Trump also wrote that Queen Elizabeth II "was respected and beloved by the American People like few other figures in modern times."
After Queen Elizabeth II died, Charles III was formally proclaimed as king during a meeting by the Accession Council on Saturday.
Trump said that King Charles III "will be a great and outstanding successor to his cherished mother."
The Associated Press and Caitlin McFall contributed to this report.