Maurice Strong, whose work helped lead to the landmark climate summit that begins in Paris on Monday, has died at 86, the head of the UN's environmental agency said Saturday.

"Strong will forever be remembered for placing the environment on the international agenda and at the heart of development," Achim Steiner, executive director of the UN Environment Program, said in a statement Saturday.

The statement did not provide details of Strong's death.

Manitoba-born Strong, the first UNEP chief, organized the Rio Earth Summit in 1992, which led to the launch of the UN Framework Convention on Climate Change.

Christiana Figueres, the current head of the UN climate agency, tweeted Saturday that "we thank Maurice Strong for his visionary impetus to our understanding of sustainability. We will miss you." 

'It seems impossible to think that he is no longer with us, that we will not have his good counsel when we lose our way.' - Felix Dodds

Prime Minister Justin Trudeau, who is in Paris for the climate talks, said Strong will be remembered as a pioneer of sustainable development.

"Mr. Strong was an internationally recognized environmentalist and philanthropist who used his remarkable business acumen, organizational skills and humanity to make the world a better place," said Trudeau in a statement.

In 1976 Mr. Trudeau's father, then prime minister Pierre Trudeau, made Strong the first head of the national oil company Petro-Canada.

Steiner said Strong's work helped usher in a new era of international environmental diplomacy at the 1972 Stockholm Conference, which saw the birth of UNEP, the first UN agency to be headquartered in a developing country.

'Leader, mentor and friend'

As head of UNEP, Strong convened the first international expert group meeting on climate change. Steiner urged the international community to honor Strong's vision by adopting a climate deal in Paris.

"The sustainability roadmap which started in Stockholm, continued in Rio, Johannesburg and Rio+20, must now become a reality in Paris," Steiner said. "This would indeed be the most fitting tribute to the legacy of Maurice Strong; leader, mentor and friend."

Strong held several other positions at the UN, and earlier in his career he led the Canadian International Development Agency.

Author Felix Dodds issued a statement saying that he worked with Strong on his last book, Only One Earth: The Long Road via Rio to Sustainable Development.

"It seems impossible to think that he is no longer with us," said Dodds, "that we will not have his good counsel when we lose our way."

Strong, born in 1929 in Oak Lake, Man., was a companion of the Order of Canada and a member of the Queen's Privy Council for Canada.

With files from CBC News