How Prince Harry Is Making a Difference 25 Years After His Mom Princess Diana's Iconic Landmine Walk

prince-harry-3-2000
prince-harry-3-2000

PA Wire/PA Images (2) Prince Harry in 2019 and Princess Diana in 1997

Twenty-five years ago, Princess Diana stepped out onto an active minefield in Angola to aid in the call for an international ban on landmines.

Now, decades later, her son Prince Harry is the only other person who matches his late mother's impact on the ongoing issue to rid the world of landmines.

That's the opinion of a man who joined the Duke of Sussex more than two years ago when he walked in the footsteps of Diana in a former warzone in Angola.

In 2019, Harry visited the same town, Huambo, where his mother made her trailblazing walk through an area being cleared by the charity HALO Trust on January 15, 1997.

"There's no comparison to the public attention that we get in moments like that with Prince Harry to anything else, not just HALO does, but the entire cause of organizations who work to remove landmines or to assist the victims thereafter through medical services," Chris Whatley, HALO USA's Executive Director, tells PEOPLE.

He continues, "Nothing gets the attention, whether it be at the highest level of governments or whether it's the boy scout troop that makes a small contribution on which we depend, and all of that is amplified and accelerated by Prince Harry because of this dynamic relationship between who he is as his own person, his own service, his own set of causes and his unique ability to connect with people."

RELATED: Prince Harry Meets Landmine Victim 22 Years After She Shared Special Moment with Princess Diana

And, of course, ahead of Harry was the late princess, "who sits out there as this continuing moral presence in the cause," Whatley adds.

prince-harry-3-2000B
prince-harry-3-2000B

PA Wire/PA Images; Dominic Lipinski/PA Wire/PA Images Princess Diana and Prince Harry

Diana made the issue such an important one in the last year of her life.

"As soon as Princess Diana made her walk, it became a front of mind issue," he says of her visit to Angola. "It took the convening power of Princess Diana to do that, to put it on the world stage to create that public momentum that, that allows for the political support, the rallying that continues to this day."

Following Diana's death in 1997, one of her key legacies was the signing of the Ottawa Mine Ban Treaty, which called for all countries to unite to rid the world of landmines.

When Harry visited the town of Huamba in September 2019, Whatley was with him.

"He's a very approachable and dynamic guy. He walked down exact same street and there's a hospital on one side, there's a school on the other," he recalls. "There are all of these kids in the white uniforms lined up to greet him and sing, and he's there interacting with them. But then he pauses at the memorial, there's a tree leftover from that moment and the memorial for her. And you could empathize with him. There was an authentic moment of connection to his mother and her cause."

A lot has changed in the area since Diana made her famous walk — a testament to Diana's efforts and the work of HALO and others.

Diana Minefield
Diana Minefield

Tim Graham/Getty Images Princess Diana

"You could see that the presence of all that infrastructure, all those people, the houses on one side, people on their balconies cheering, all of that is a result of her presence 25 years ago. Had she not showed up there, this would still be a bombed-out hulk of a street," Whatley says.

That day was emotional for Harry, especially when he spoke publicly.

"You could see it in his expression — there was a kind of tension between his connection to his mom and realizing that he's in a place that was so much a part of who she was then and what her legacy is now," Whatley shares. "It was such a specific resonance to his mother who he obviously loves and continues to mourn. And then there was the kind of excitement and energy that you get when you see how much has changed and how much impact that she made and how much gratitude he was feeling."

The Duke of Sussex
The Duke of Sussex

PA Wire/PA Images The Duke of Sussex walks through a minefield in Dirico, Angola, during a visit to see the work of landmine clearance charity the Halo Trust, on day five of the royal tour of Africa.

Can't get enough of PEOPLE's Royals coverage? Sign up for our newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

Back in 2017, Harry pledged his ongoing support to make the world free of landmines by 2025. Whatley believes that, while progress is being made, it is a tough target.

"War and other factors are making that difficult, but there are key countries who will get across that finish line," he says. "Zimbabwe's one, Sri Lanka is another and the voice of Prince Harry is key for maintaining that momentum. We will witness fantastic progress, but I still think that there will be more work to be done. And as a result, his voice is needed more than ever."

Whatley says in the U.S., both Republicans and Democrats have agreed on the support that is needed for organizations like the HALO Trust, which are clearing landmine areas. Since Diana made it such a prominent issue, 80 percent of the world's deadly mines have been cleared, Whatley says. But HALO is still spending around $120 million around the world with 10,000 operatives helping to make communities safe.

Prince Harry, Duke of Sussex
Prince Harry, Duke of Sussex

Dominic Lipinski/PA Images Prince Harry

Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

Reflecting on Diana's first visit (she later visited Bosnia, shortly before her death), he adds, "It's such a striking juxtaposition of the most famous woman in the world and this remote dangerous, desperately conflict setting. Angola was really at the sharp end of the stick of the global crisis at that moment in 1997. The imagery of that visit itself was just so compelling. Every American put that image in their head even if they're not that interested in foreign affairs."

He adds, "It's her voice that's maintaining the drumbeat, echoed now by her son."