Leonardo DiCaprio has been named a United Nations Messenger of Peace.

The 39-year-old actor was appointed to the role by UN Secretary General Ban Ki-moon to help promote the organisation's global action on climate change.

Ki-moon described the 'Wolf of Wall Street' star - who established his own foundation to help promote the earth's remaining wildlife environments in 1998 - as ''not just one of the world's leading actors'' but as also having ''a longstanding commitment to environmental causes.''

According to the New York Post newspaper's Page Six column, Leonardo is set to attend next Tuesday's (23.09.14) climate summit where he will address 120 world leaders on the topic.

The Oscar-winner said he feels ''a moral obligation to speak out at this key moment in human history'' and is honoured to have taken on the role in a bid to tackle the threat of climate change.

Leonardo joins a host of other renowned names who have become United Nations Messengers of Peace including Stevie Wonder, Michael Douglas, George Clooney, Brazilian author Paulo Coelho and conductor Daniel Barenboim.

<3333