Prime Minister Justin Trudeau's debut appearance at the Commonwealth Heads of Government meeting in Malta saw him greeted with applause by his fellow leaders as he announced Canada's latest contribution towards an international climate fund.

As his day ended, the Canadian prime minister was chosen to toast the Queen at a special banquet hosted by the monarch on the first evening of the three-day gathering of 53 Commonwealth countries.

"You were only nine years old when you carried out what was perhaps your first official duty on behalf of Canada — an appearance on a postage stamp. That was 1935," Trudeau said in a text distributed by his staff. He paid tribute to her "constant presence in the life of Canada" since then.

"It is safe to say that you have seen more of Canada than almost any Canadian. And always, Canadians have watched and admired their indefatigable queen, forming cherished memories."

The Queen is attending with her husband, Prince Phillip, her son Prince Charles and his wife, Camilla, the Duchess of Cornwall. This summit could be the last Commonwealth gathering for the 89-year-old monarch, who no longer travels long distances.

The summits are only held every two years and the next two are scheduled to be far from Europe.

It's unusual to have four members of the Royal Family attend an international event at the same time. As a result, security is very tight.

As she opened the Summit Friday, the Queen praised the accomplishments of the Commonwealth.

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Prime Minister Justin Trudeau walks with his wife Sophie Grégoire-Trudeau as they arrive at the Commonwealths Heads of Government meeting in Valletta, Malta on Friday. (Adrian Wyld/Canadian Press)

"Prince Philip and I first came to live here in Malta in 1949, the year the Commonwealth was founded," she said, hailing a vast advancement in freedom and human rights in the decades since then.

"I have been privileged to witness this transformation and to consider its purpose."

Between 1949 and 1951, Philip was stationed on Malta as a Royal Navy officer and the future queen lived as a military wife, rather than a duty-burdened heir to the throne.

Commonwealth leaders are grappling with some difficult issues, including corrupt governance among their ranks, the renewed push for meaningful action on climate change, as well as security concerns, in an era of violent attacks like those ISIS mounted most recently on Beirut and Paris.

In 2016, the United Kingdom will host an anti-corruption summit. At this year's gathering, advocacy group Transparency International and Joseph Muscat, Malta's prime minister, issued a statement about the lead role Commonwealth countries can play to ensure public funds are not stolen or laundered.

"Unchecked, corruption can choke off development, rob people of faith in their governments and sow the seeds of instability and conflict," it read.

'Training camp' for Paris

The special session on climate change was attended by French President François Hollande, who was invited to come long before the recent Paris attacks.

Starting Monday, Paris will play host to the UN climate summit, COP21, where more than 190 countries will gather to craft a new climate deal aimed at curbing greenhouse gases.

Hollande took no questions from reporters, but praised Canada for Trudeau's announcement new funding to help developing countries deal with climate change.

UN Secretary General Ban Ki-moon and Prince Charles, who has long been interested in the environment, were also part of the session, where leaders were encouraged to "raise your voices" in the fight to curb greenhouse gas emissions.

Prince Charles met separately with Prime Minister Justin Trudeau and the Canadian delegation early Friday afternoon.

Justin Trudeau meets Prince Charles0:25

Canada's Foreign Affairs Minister Stéphane Dion portrayed the session as a "good training camp" for the crucial climate summit in Paris.

He told reporters that debates were already "lively" in the preparatory meetings leading up to this week.

Many of the Commonwealth countries include small island nations that face a threat from rising sea levels. One proposal in front of the leaders would allow countries to write off their foreign debts by doing more to protect the environment.

A speech from the Queen and then straight to work in Malta3:29

Canada's role in the fight against ISIS also factors into discussions with other leaders. The new Liberal government will withdraw its six fighter jets from the U.S.-led mission, pledging instead to increase the number of military trainers on the ground.

Trudeau arrived in Malta after departing London on Wednesday, when British Prime Minister David Cameron had made a strong case before his own Parliament to expand the mission of British fighter jets into Syria.

Trudeau will move on to Paris on Saturday afternoon, in preparation for bilateral talks Sunday with Hollande in advance of COP21.

With files from Margo McDiarmid, Rosemary Barton, The Associated Press and The Canadian Press