President Donald Trump and first lady Melania Trump, on the third day of their U.K. trip, joined Queen Elizabeth II and more than 300 D-Day veterans in Portsmouth on Wednesday for a national ceremony of remembrance on the 75th anniversary of the allied military invasion remembered as a turning point of World War II.

Portsmouth, a major port city in southern England, was the launching point for D-Day landings on June 6 and the home of Southwick House, headquarters for allied commander U.S. Gen. Dwight D. Eisenhower.

President Trump, seated next to the queen in the royal box listened to tributes and performances commemorating the 1944 Normandy landings.

After reviewing honor guards from the Royal Navy, Army, Air Force and Welsh Guards, the president took the stage to read the prayer President Franklin D. Roosevelt delivered to the nation by radio on the evening of June 6, 1944, addressing the Normandy operation.

“Almighty God: Our sons, pride of our Nation, this day have set upon a mighty endeavour, a struggle to preserve our Republic, our religion, and our civilization, and to set free a suffering humanity," Trump read in an excerpt.

Veterans of the 1944 invasion sat near the front for the ceremony with ribbons and medals on their chests. In addition to the queen, Trump was joined by Prince Charles, U.K. Prime Minister Theresa May, German Chancellor Angela Merkel, French President Emmanuel Macron and Canadian Prime Minister Justin Trudeau in the special tribute at Southsea Common.

Trump, May, Macron and Trudeau read special tributes to their individual country's contributions, and the queen delivered an address before a Royal Navy frigate fires a naval salute and 25 historic and U.K. military aircraft fly over the proceedings.

Queen Elizabeth stated when she attended the 60th anniversary of D-Day, many believed it would be the last such commemoration. “But the wartime generation - my generation - is resilient, and I am delighted to be with you in Portsmouth today,” the 93-year-old queen said.

Following the ceremony, the president, first lady, the queen, Prince Charles and Macron met with a dozen D-Day veterans. Some 300 of them were headed to board the Royal British Legion's ship to depart for Normandy.

Trump and the queen bid each other farewell and taking a photo. “It was a great honor to be with you,” the president said to the queen calling her a "great woman."

On Thursday, the president will travel to Normandy to visit the Normandy American Cemetery in Colleville-sur-Mer, observe re-enactments of airborne landings and participate in a Commemoration of D-Day Program alongside veterans who stormed the beaches.

The two days of events are expected to be the last that many surviving World War II veterans are able to attend. From D-Day through Aug. 21 of that year, the Allies landed more than 2 million troops in northern France and suffered more than 226,000 casualties.

"More than one-and-a-half million American service members were stationed right here in England in advance of the landings that summer," Trump said of Portsmouth during a press conference with May on Tuesday. "The bonds of friendship forged here and sealed in blood on those hallowed beaches will endure forever."

May said the event aims to "reaffirm the enduring importance of the Western alliance and the shared values that underpin it."

After the Portsmouth celebration, the Trumps were headed to Shannon, Ireland, for a meeting with Irish Taoiseach Leo Varadkar before heading to Normandy.

ABC News' Rachel Scott contributed to this report.