US President Donald Trump has joined the UK’s Prime Minister Theresa May and representatives from 14 other countries in Portsmouth on Wednesday, where they signed a D-Day proclamation pledging to work together to “resolve international tensions peacefully”. The commemoration of the 75th anniversary of the D-Day landings - the allied invasion of northern France during the Second World War - coincides with the final day of the president’s state visit to the UK. Mr Trump read the same prayer read by President Roosevelt ahead of the D-Day landings at the ceremony, in which he was also joined by Queen Elizabeth II and 300 veterans, the youngest of whom are in their 90s. Speaking at the event, the 93-year-old British monarch expressed her gratitude to the veterans on behalf of the “whole free world”. She said: "When I attended the commemoration of the 60th anniversary of the D-Day landings, some thought it might be the last such event. "But the wartime generation, my generation, is resilient." Canadian prime minister Justin Trudeau, German Chancellor Angela Merkel and France’s president Emmanuel Macron were among the world leaders who travelled to Portsmouth, which was the departure point for the largest seaborne assault in history, involving 156,000 US, British, Canadian and other Allied troops. The signatories of the proclamation must commit to ensuring the horrors of the war are never repeated again. "Over the last 75 years, our nations have stood up for peace in Europe and globally, for democracy, tolerance and the rule of law," the statement reads. "We re-commit today to those shared values because they support the stability and prosperity of our nations and our people. We will work together as allies and friends to defend these freedoms whenever they are threatened." In an interview earlier on Wednesday with British broadcaster <em>ITV,</em> Mr Trump said there was <a href="https://www.thenational.ae/world/mena/donald-trump-prepared-to-talk-to-iran-but-says-chance-of-military-action-1.870643">"always a chance" the US would go to war with Iran</a> if Tehran developed its nuclear weapon programme. However, Mr Trump added that he did not want to go to war and would be prepared to talk with Iran’s president Hassan Rouhani. In a wide-ranging interview, the president said those who fought in D-Day had paid the "ultimate debt". "That may have been the greatest battle ever in history," he said. The president met Conservative Party leadership hopeful Jeremy Hunt on Wednesday morning before the ceremony. Mr Trump spoke to Boris Johnson, another candidate hoping to replace Mrs May when she resigns on Friday, over the phone on Tuesday evening. Tweeting on Wednesday morning, the president said he could see a "very big Trade Deal" between the two nations in the future. The president flew to Ireland after the commemorations, where he will hold talks with Irish prime minister Leo Varadkar and visit <a href="https://www.thenational.ae/world/europe/donald-trump-s-global-golf-tour-hits-ireland-1.869321">his golf course, Doonbeg.</a>