Roger Federer, the Swiss world number one tennis player, has been appointed Goodwill Ambassador for the United Nations Children's Fund (Unicef).
He joins the ranks of footballer David Beckham, pop singer Shakira and screen stars Sir Roger Moore and Whoopi Goldberg.
Speaking at Unicef headquarters in New York on Monday, Federer said he felt honoured to be part of efforts to help children across the world who don't have the basic means to survive.
"It is our responsibility to connect the real world beyond our sport, to use our fortune to make a difference in the lives of those who most need it," he said.
The winner of seven Grand Slam titles said he had been fortunate in his life to be able to pursue what he liked to do most – playing tennis since the age of six.
On Sunday Federer clocked up his 37th ATP title, winning the final against Ivan Ljubicic at Key Biscayne, Florida.
Champion of charity
The 24-year-old Swiss has been involved in charity work for several years. He set up a foundation in 2003 which promotes tennis worldwide and cooperates with a non-governmental organisation to help young people in South Africa, where his mother was born.
The Roger Federer Foundation is working with Imbewu, which runs development projects and sponsors schooling for children in a township outside the city of Port Elizabeth.
Federer also supported the launch of the International Year of Sports and headed up several Unicef fundraising campaigns for the victims of the 2005 tsunami in southeast Asia.
Unicef executive director Ann M. Veneman said Federer was not only a model for young athletes but also for all those people who believed in the power and responsibility to make the world a better place for children.
Elsbeth Müller of Unicef Switzerland said she was delighted with the nomination of Federer as international Goodwill Ambassador.
"Roger Federer will be a huge asset for Unicef. He's an ideal representative for us because he has charisma and integrity and is recognised around the world."
swissinfo with agencies
Unicef Goodwill Ambassadors are active on a national, regional and international level to support projects aimed at improving the lives of children.
The first Goodwill Ambassador was the US actor Danny Kaye in 1954. The list includes screen stars such as the late Audrey Hepburn, Sir Roger Moore and Whoopi Goldberg, as well as singers Angélique Kidjo and Harry Belafonte.
Roger Federer is only Switzerland's second Goodwill Ambassador. English-born Sir Peter Ustinov, who later took Swiss nationality, had been Goodwill Ambassador for more than 35 years when he died in 2004.