William poses for selfies as he arrives in Rio for Earthshot Prize

The Prince of Wales was presented with the keys to Rio de Janeiro as he began a five-day visit to Brazil.

Prince William was on the city's Sugarloaf Mountain, with a bird's eye view of the iconic Christ the Redeemer statue, as he received the honour from the city's mayor, Eduardo Paes.

The prince had travelled to the top of the mountain by cable car, to the surprise of several groups of tourists queuing to travel up the mountain. As he came down again, he posed for selfies with several of the people who had waited to catch a glimpse of him.

He is visiting Brazil for the first time with two key environmental missions. On Wednesday he is presenting the Earthshot Prize, the annual award from the charity he set up himself.

The following day he will travel to Belem, in the Amazon rainforest, where he is scheduled to deliver a speech as part of COP30, the annual UN climate meeting where governments discuss how to limit and prepare for further climate change.

It is the first time that Prince William has travelled internationally for a COP summit, as his father, King Charles, has previously led the way for the royals, making several keynote speeches to world leaders over the years.

Prince William did attend, along with his father, when it was held in Glasgow 2021, two weeks after the first Earthshot Prize.

The prize annually awards a £1m grant in five different categories for projects that aim to repair the world's climate - and Prince William has committed himself to it for10 years, with Rio marking a halfway point for the venture.

This year's shortlist includes an upcycled skyscraper in Sydney, the entire island of Barbados and a Bristol based company that filters microplastics from washing machines.

When he announced the nominees, the prince spoke of the optimism and courage he was looking for.

"The people behind these projects are heroes of our time, so let us back them. Because, if we do, we can make the world cleaner, safer and full of opportunity - not only for future generations, but for the lives we want to lead now."

After the ceremony, Mayor Paes said Prince William has been "amazed with the beauty of the city" and he joked: "So he's got the keys, he can do whatever he wants in the next 72 hours. The city belongs to Prince William. I'm still the king, but it will belong to him!"

Prince William's visit to Rio de Janeiro is the most significant royal engagement he will make this year and also mark the first time he will be seen representing the Royal Family since the crisis surrounding his uncle Andrew.

There has been speculation that Prince William was heavily involved in the King's announcement last week to sanction Andrew by removing his remaining titles and asking him to leave his home in Windsor - but those close to the situation say that was not the case.

Although William would have had a powerful, influential voice as the future monarch, the decision was ultimately the King's working with his private team of advisers and in conjunction with the government.

The visit to Brazil will include the two key environment-based events but will also allow him to take in some of Rio's other famous sights.

As an avid football fan and chairman of the English Football Association, it was no surprise that a pilgrimage was arranged on his first day to the Maracana Stadium, the stage of some of the football-mad nation's most famous moments.

Once there, he was greeted by the player who wore the yellow and green kit more than any other, Brazil's most capped-star Cafu, who presented him with a signed number 2 Brazil shirt.

The legendary right back, who is the only player in history to appear in three World Cup finals, was scheduled to join the prince leading training drills involving local children.

Cafu has also agreed to be one of the star presenters of the Earthshot Prize, alongside former F1 driver Sebastian Vettel, Olympic gymnast Rebeca Andrade and Brazilian environmental activist Txai Suruí.