King Charles has extended his "warmest congratulations" to President Donald Trump and the American people as the US marks the 250th anniversary of its independence from Britain. The monarch described the occasion as "a truly historic milestone and a moment of great celebration for Americans everywhere".In his message, the King highlighted his and the Queen’s personal connection to the milestone, stating they were "proud, and honoured, to be able to celebrate this special anniversary during our visit to the United States in April". He reflected on the enduring relationship between the two nations, characterising its history as "one of extraordinary evolution, from overcoming conflict to forging one of the closest and most productive alliances the world has seen".The royal couple’s four-day trip to the US earlier this year was specifically timed to commemorate the quarter-millennium anniversary of American independence. The King and Donald Trump at the state dinner at the White House in April (Aaron Chown/PA) (PA Wire)Their itinerary included a tea at the White House with Mr Trump and his wife Melania, a lavish white-tie banquet held in their honour, a significant address to Congress, and a festive, bunting-adorned street party in rural Virginia. This visit followed Mr Trump’s second state visit to the UK last September.The message, posted online, said: “Dear Mr President,“My wife and I are delighted to send our warmest congratulations to you and to the people of the United States of America on the occasion of the 250th anniversary of your nation’s independence.“We were proud, and honoured, to be able to celebrate this special anniversary during our visit to the United States in April.“This year marks a truly historic milestone and a moment of great celebration for Americans everywhere.“It offers an opportunity to pause and reflect on the remarkable journey of the United States over the past two-and-a-half centuries, and to honour all that has been achieved since 1776.“The story of the relationship between our two nations is one of extraordinary evolution, from overcoming conflict to forging one of the closest and most productive alliances the world has seen.“Across defence and security, trade and investment, science, research, education, culture and the arts, the ties between the United Kingdom and the United States are unique and far-reaching.“Together, we face the challenges of today, and the opportunities of tomorrow. As I said in my address to the joint Houses of Congress, our shared roots run deep, and they are still vital.“I am greatly encouraged by the enduring bond between our countries, and by the many connections between our peoples, which we were able to see once again, at first-hand, on our visit.“Through centuries of shared challenge and achievement, our nations have built a relationship founded on friendship, trust and a belief in liberty, the rule of law and the dignity of all people.“As we look ahead to the next 250 years, I have no doubt we will continue to defend our shared values.“I also hold a deep appreciation of our shared responsibility to protect the natural world, knowing the decisions we take today will determine whether our critical natural systems will not just maintain the harmony and essential diversity of nature, but also continue to provide the foundation for our prosperity and our national security for both present and future generations.“The connection between our peoples is one that I trust will only grow stronger with time.“As you mark this momentous occasion, my wife and I send our warmest good wishes to you and to the people of the United States of America, today and in the years ahead.“Charles R.”