The Duke of Sussex has called for the sacrifices of Nato troops to be “spoken about truthfully and with respect”, after the US president claimed allies stayed “a little back” from the front lines in Afghanistan.

“I served there. I made lifelong friends there. And I lost friends there,” Prince Harry, who was twice deployed to the country, said on Friday as he paid tribute to Nato troops killed in the conflict, including 457 UK service personnel.

The prince was reacting to controversial comments made by Donald Trump in an interview on Thursday.

Trump’s words have drawn condemnation from international allies, with Prime Minister Sir Keir Starmer calling them “insulting and frankly appalling” .

The UK and other nations joined the US in Afghanistan after Nato’s collective security clause was invoked following the 9/11 attacks.

Prince Harry said: “In 2001, Nato invoked Article 5 for the first – and only – time in history. It meant that every allied nation was obliged to stand with the United States in Afghanistan, in pursuit of our shared security. Allies answered that call.”

He added: “Thousands of lives were changed forever. Mothers and fathers buried sons and daughters. Children were left without a parent. Families are left carrying the cost.

“Those sacrifices deserve to be spoken about truthfully and with respect, as we all remain united and loyal to the defence of diplomacy and peace.”

The duke’s comments follow Trump’s Fox News interview in which he said: “We’ve never needed them. We have never really asked anything of them.

“They’ll say they sent some troops to Afghanistan… and they did, they stayed a little back, a little off the front lines.”

The president also said he was “not sure” the military alliance would be there for the US “if we ever needed them”.

In the UK, Trump’s remarks were condemned across the UK’s political divide.

Shortly before the prince’s statement, Sir Keir gave his own reaction saying if he himself had “misspoken in that way” he would “certainly apologise”.

Sir Keir said: “I will never forget their courage, their bravery and the sacrifice they made for their country.

“There were many also who were injured, some with life-changing injuries.

“I consider President Trump’s remarks to be insulting and frankly appalling and I am not surprised they have caused such hurt to the loved ones of those who were killed or injured and, in fact, across the country.”

Outside of the UK, ministers from foreign governments also criticised Trump’s remarks.

Poland’s foreign minister Radoslaw Sikorski, who was among 33,000 Polish troops who served on the frontline in Afghanistan, said: “No one has the right to mock the service of our soldiers”.

Canada’s Minister of National Defence David J McGuinty said that Canadian “men and women were on the ground from the beginning, not because we had to, but because it was the right thing to do.”

He said 158 of their troops “paid the ultimate price” for leading allied efforts in the Kandahar Province.

Jaap de Hoop Scheffer, former secretary general of Nato during the Afghanistan War, told the BBC World Service: “No American president should have the liberty to belittle their legacy and to insult the ones who are still grieving the fact that they didn’t come back alive from Afghanistan.

“What I would expect is a sincere apology from the president of the United States.”

In October 2001 the US invaded Afghanistan to oust the Taliban, whom they said were harbouring Osama Bin Laden and other al-Qaeda figures linked to the 9/11 attacks. Nato nations contributed troops and military equipment to the US-led war.

More than 3,500 coalition soldiers had died, about two-thirds of them Americans, as of 2021 when the US withdrew from the country. The UK suffered the second-highest number of military deaths in the conflict behind the US, which saw 2,461 fatalities.

Most of the 457 British troops who died serving in Afghanistan over a period of nearly 20 years were killed in Helmand – the scene of the heaviest fighting.

Hundreds more suffered injuries and lost limbs – including Cpl Andy Reid who lost both his legs and his right arm after stepping on an improvised explosive device (IED) in Afghanistan.

“Not a day goes by when we’re not in some kind of pain, physically or mentally reflecting on that conflict,” he told BBC Breakfast.

Reid recalled working with American soldiers during his time in Afghanistan, adding: “If they were on the front line and I was stood next to them, clearly we were on the front line as well.”

Diane Dernie, whose son Ben Parkinson suffered severe injuries when an Army Land Rover hit a mine near Musa Qala in 2006, said Trump’s words were “so insulting” and hard to hear.

The 41-year-old is currently recuperating after another operation, but Dernie told the BBC that Trump’s comments showed “a childish man trying to deflect from his own actions”.

Dernie called on Starmer to “stand up for his own armed forces” and call out the US president.

Her comments were put to the prime minister who replied: “I’ve made my position clear, and what I say to Diane is, if I had misspoken in that way or said those words, I would certainly apologise and I’d apologise to her.”

Giving a second interview to the BBC moments after Starmer’s statement, Dernie said the prime minister’s words were strong enough – but said he should go further.

“His words were exactly what we wanted to hear, but we need those words to be addressed directly to the president,” Dernie said. “I appreciate what Starmer has said, but they need to be said to Donald Trump.”

Throughout Friday, the leaders of the main Westminster political parties gave their reaction to Trump’s comments.

Conservative leader Kemi Badenoch said: “I spoke to parents of young men who have lost their lives. It is a disgrace to denigrate their memory like that.

“There is too much careless talk from President Trump. He clearly doesn’t know the history of what happened. We must not have these sorts of throwaway remarks.”

Liberal Democrat leader Sir Ed Davey criticised the US president’s remarks and said: “Trump avoided military service five times. How dare he question their sacrifice.”

Trump received five deferments from a military draft during the Vietnam War – four for academic reasons and one for bone spurs, a calcium build-up in the heels.

Reform UK leader Nigel Farage said: “Donald Trump is wrong. For 20 years our armed forces fought bravely alongside America’s in Afghanistan.”

American political and military figures have also expressed their anger and frustration over Trump’s Nato comments.

Former national security adviser Herbert Raymond McMaster, who served as senior US officer in Afghanistan, said British forces were engaged in counter-insurgency operations every day.

“I think it’s insulting to those who were fighting alongside of us,” McMaster told the BBC.

“What I would like him to say is to make amends by affirming our gratitude for our allies who fought alongside us, and especially those who made the ultimate sacrifice in a war that I think was important, obviously, to the future of all humanity.”

During his second term in office, Trump has repeatedly criticised Nato, often accusing its member states of not spending enough on defence.

In the last few weeks, Trump has made comments about acquiring Greenland – a semi-autonomous territory of fellow Nato ally Denmark.

Trump’s repeated remarks over ownership, threats of military action and tariffs against traditional European allies have rattled the transatlantic treaty.

The White House has remained pretty quiet on the outrage being expressed in Britain – partly because the story has not played big in the US, and because Trump has been otherwise occupied, not making his usual appearances in front of cameras to have questions thrown at him.

On Friday – before Starmer called on the US president to apologise – the White House released a statement sticking by Trump’s long-held view on Nato.

The White House said: “President Trump is right – America’s contributions to Nato dwarf that of other countries, and his success in delivering a 5% spending pledge from Nato allies is helping Europe take greater responsibility for its own defense.

“The United States is the only Nato partner who can protect Greenland, and the president is advancing Nato interests in doing so.”

The White House is yet to comment on Starmer’s suggestion for an apology.