The Prince of Wales has spoken of his “much-missed Grandmother” as he delivered his first speech since the King bestowed him with his new title.

William, who is now heir to the throne following the death of the Queen, addressed the United for Wildlife (UfW) global summit at the Science Museum in London.

In his keynote speech – on a topic he has long campaigned on – William warned that illegal wildlife crime is destroying too many lives and pushing too many species towards extinction.

William, 40, said: “I’m delighted you could all join us today. It’s heartening to see so many familiar faces whilst welcoming many new ones as well.

“You being here is a testament to how far United for Wildlife has grown.

“Our natural world is one of our greatest assets. It is a lesson I learnt from a young age, from my father and my grandfather, both committed naturalists in their own right, and also from my much-missed grandmother, who cared so much for the natural world.

“In times of loss, it is a comfort to honour those we miss through the work we do.

“I take great comfort, then, from the progress we are making to end the illegal wildlife trade.”

The summit, hosted by Lord Hague – chairman of The Royal Foundation of the Prince and Princess of Wales – brought together more than 300 global leaders from law enforcement agencies, conservation organisations and private sector companies who are part of the UfW network.

It saw speakers announce new policies and unveil partnerships in a bid to end the trade, which is worth up to 20 billion dollars (£17 billion) per year and is associated with violent crime, corruption and other forms of trafficking.

Observers will likely see William’s speech as him setting out his continued commitment to campaigning on the issue of wildlife crime in his new role as Prince of Wales.

In July, William paid tribute to “committed and brave” ranger Anton Mzimba, who was reportedly shot and killed outside his home.

William called for those responsible for the death of the conservationist, who worked in South Africa, to be “swiftly brought to justice”.

Mr Mzimba was head of ranger services at Timbavati private game reserve in north-east South Africa, near the Kruger National Park.

He spoke to William via video link last autumn, when the royal visited a technology company to learn about a new device to combat ivory smugglers.

Ahead of his speech on Tuesday, William met Altin Gysman from the Southern African Wildlife College (SAWC), who was a friend and colleague of Mr Mzimba.

William described the death as a “shocking moment” and referred to rangers being “on the front line”.

The prince said: “There’s a front line and that’s the worrying thing. There’s a war going on and everyone doesn’t really see it.”

William said the last statistic he had heard was that in the last 10 years more than 1,000 rangers have lost their lives on the continent of Africa protecting wildlife and communities.

“It’s terrifying. It really is,” he said.

Later in his speech, William said: “Eight years ago, we set out to develop a solution to one of the largest, yet often overlooked, international crimes blighting our world.

“A crime that robs us all of our most precious natural resources and funds organised crime, the harms of which are often directly felt by the most vulnerable communities.

“And a crime that this year felt especially brutal.

“The devastating news about Ranger Anton Mzimba is shocking confirmation of how vicious the illegal wildlife trade is.

“Anton dedicated himself to the protection of wildlife, undertaking his role diligently and professionally despite threats to his life.

“He stood up to violent criminals and paid the ultimate price. It is only right that we pay tribute to him and all the other selfless rangers and frontline conservationists here today.

“And it is also only right that we honour him by continuing our work with renewed focus and vigour.”

William told the audience: “Looking ahead, I am pleased to announce that the East and Southern Africa Anti-Money laundering Group, comprising 19 countries, will formally enter into an agreement with United for Wildlife, marking the first international public-private partnership for any financial crime.

“Thanks to your collaboration and forward thinking, our activity is having a demonstrable impact.

“And while we do not have the luxury of time, clearly we do have a proven roadmap to success and the motivation to put it into action.

“I hope you all leave here today energised and motivated to intensify this work.

“Because there are still too many criminals who believe they can act with impunity, too many lives being destroyed, and too many species on the brink of extinction due to this heinous crime.”

William was made the Prince of Wales by his father Charles, who announced his decision in a historic television address to the nation on September 9, the day after the death of the Queen.

The prince set up UfW in 2014 to tackle the illegal trade in animal products.

He has long campaigned against illegal wildlife trade, previously calling for a commitment to end the “abhorrent crime” which includes the poaching of elephants for ivory and tigers for their skins.