Secretary General Ban Ki-Moon appointed Leonardo DiCaprio as a United Nations Messenger of Peace, reports MSN News.

As part of his new duties as U.N. Messenger of Peace, the "Wolf of Wall Street" star is set to help in the campaign of worldwide awareness on climate change.

In a news conference on Tuesday, Ban said that DiCaprio is not just a great Hollywood actor but he is also a well-known advocate of the environment.

"Mr. DiCaprio is a credible voice in the environmental movement, and has a considerable platform to amplify its message," said the U.N. secretary-general.

Ban added, "His global stardom is the perfect match for this global challenge."

On Sept. 23, Dicaprio is scheduled to speak at the U.N. Climate Summit before 120 world leaders to talk about the current climate condition, according to Climate Summit 2014.

DiCaprio said that he is privileged to be chosen to be a United Nations Messenger Peace, according to Yahoo News,

"I feel a moral obligation to speak out at this key moment in human history - it is a moment for action," the environmentalist said.

He continued, "How we respond to the climate crisis in the coming years will likely determine the fate of humanity and our planet."

In 1998, the American actor started a foundation with the aim of promoting a more balanced relationship between mankind and Mother Earth. The foundation also helps in preserving last wild places of the planet and prevention of global warming, reports the Associated Press.

The environmental activist earned a Golden Globe Award for Best Actor for his performance in the "Aviator" and "The Wolf of Wall Street." Other movies that made him an international star are "Titanic," "Inception," "Catch Me If You Can," "The Departed" and "Romeo and Juliet."

Other famous personalities who hold the same title in the United Nations include Stevie Wonder, Michael Douglas, George Clooney, Brazilian author Paulo Coelho, primatologist Jane Goodall and conductor Daniel Barenboim.