The 28-year-old, who is patron of the Halo Trust's 25th Anniversary Appeal, travelled to Cuito Cuanavale in Angola earlier this month to see the charity's mine clearance work. The charity was famously championed by his mother.
The young royal is frustrated that countries that had supplied the landmines previously are not funding their clearance.
Prince Harry toured an Angolan minefield earlier this month just as his mother did in 1997
"He is irritated about the countries that supplied these landmines are not actually putting in any funds to clear them 25 years later," said the charity's chief executive Guy Willoughby.
"He has got quite a bee in his bonnet about that, and that is good.
"The commitment shown by Prince Harry plays an invaluable role in helping us to raise awareness of Halo's work and mission."
Harry with HALO's chief executive Guy Willoughby in August
Guy also praised Harry for his people skills and understanding of the situation.
"He is technically very competent but he's also very good with dealing with the people, the villagers, the de-miners and he understands the big issue, even the political issue.
"Wars may be over but many people are still unable to resume their normal lives, facing the threat of death or injury by landmines every day."
Diana raised the profile of the cause when she visited in 1997
The late Princess Diana visited the minefield being cleared by the trust in Angola in 1997 shortly before her death – her concern for the situation raised the profile of the cause.
It isn't just the family connection that has seen Harry become involved in the work of the charity.
"As a soldier he is seeing so many people of his generation, of his age losing limbs. And that has really brought a focus on it," Guy told BBC news.
"I think it has brought a focus on it for a lot of the British population of seeing so many people in their 20s who are losing limbs."
Prince Harry visited the minefields in Mozambique in 2010
The Prince's trip took place earlier this month but details weren't revealed until now because the visit took place in a private capacity and there were "complicated field logistics" involved.
The town of Cuito Cuanavale in south-eastern Angola is believed to be the most densely mined town in Africa following the devastating civil war that left an estimated 500,000 people dead.
The west African nation remains one of the most heavily mined in the world despite huge efforts since the war ended in 2002 to clear the explosives.
HALO is a pioneering charity, founded in 1988, that is committed to humanitarian mine clearance around the world. Harry became patron of the Anniversary Appeal in March.
Harry has a longstanding connection with the charity and visited minefields in Tete Province, Mozambique, in 2010. During the trip Harry he met amputees, and saw the devastating impact that landmines have on some of the poorest people in mine-affected communities.