Celebrity U.N. ambassadors

David Beckham waves toward his fans while on his way back after playing a charity match to collect funds for the United Nations Children's Fund (UNICEF) at the ancient city of Bhaktapur, Nepal November 6, 2015. REUTERS/Navesh Chitrakar

David Beckham walks at Bhaktapur Durbar Square in Bhaktapur, Nepal November 6, 2015. REUTERS/Navesh Chitrakar

David Beckham kicks a ball during a charity match in Bhaktapur, Nepal November 6, 2015. REUTERS/Navesh Chitrakar

Daniel Craig gets a briefing from Cambodian de-miners at an active minefield in Cyprus, October 12, 2015. Craig spent two days in Cyprus as part of his U.N.-mandated role as global advocate against the use of landmines and explosives. A 180-km (115-mile) ceasefire line slicing through Cyprus is laced with landmines, even though the United Nations have removed thousands over the years. REUTERS/UNMAS/Handout

Angelina Jolie meets members of the Yazidi minority in Khanke internally displaced person (IDP) Camp in Dohuk, northern Iraq January 25, 2015. REUTERS/UNHCR/Andrew McConnell/Handout

Orlando Bloom high-fives with a boy as he visits the migrant transit camp in Gevgelija, Macedonia, where migrants are gathering after entering the country by crossing the border with Greece, September 29, 2015. REUTERS/Ognen Teofilovski

Katy Perry join girls playing with a jump rope during a visit to a primary school that has been rebuilt by the United Nations Children's Fund (UNICEF), after it was destroyed by a cyclone in Ampihaonana, Madagascar, April 5, 2013. REUTERS/Kate Holt/UNICEF/Handout

Salma Hayek meets with Syrian refugees during her visit with UNICEF to an informal settlement in the Bekaa valley, Lebanon April 25, 2015. REUTERS/Sebastian Rich/UNICEF/Handout

David Beckham greets victims of super Typhoon Haiyan at an evacuation center in Tacloban city in central Philippines February 13, 2014. REUTERS/Erik De Castro

Angelina Jolie hugs Neema Namadamu of the Democratic Republic of Congo at the 'End Sexual Violence in Conflict' summit in London June 11, 2014. REUTERS/Lefteris Pitarakis/Pool

Mia Farrow distributes aid to Syrian refugee children in Baalbeck, Bekaa valley, Lebanon January 15, 2013. REUTERS/Mohamed Azakir

Jackie Chan demonstrates a martial arts move in front of youth at a sports stadium in Dili, East Timor June 25, 2008. REUTERS/Lirio Da Fonseca

Angelina Jolie holds the hand of a Kachin ethnic refugee child as she visits Jam Mai Kaung IDP camp in Myitkyina, Kachin state, Myanmar, July 30, 2015. REUTERS/Soe Zeya Tun

Lucy Liu kneads dough with boys at a reinsertion center in Goma, Democratic Republic of Congo June 12, 2007. REUTERS/David McKenzie/UNICEF/Handout

Danny Glover poses with children after his arrival at a soccer stadium in Envigado, Colombia November 22, 2011. REUTERS/Albeiro Lopera

Angelina Jolie listens as an Iraqi refugee woman talks about her experience in Iraq, in Jaramana, a suburb in southern Damascus, Syria October 2, 2009. REUTERS/S.Malkawi/UNHCR/Handout

Brad Pitt, partner of Goodwill Ambassador Angelina Jolie, listens to an Iraqi refugee living in Jaramana, a suburb in southern Damascus, Syria October 2, 2009. REUTERS/UNHCR/Handout

Spain's soccer player Sergio Ramos plays soccer with children in Havana, Cuba June 16, 2015. REUTERS/Enrique de la Osa

Mia Farrow smiles as she holds a baby during her visit to a shelter in the town of Gonaives, Haiti, after a series of four storms: Hurricanes Gustav and Ike and Tropical Storms Fay and Hanna, on September 20, 2008. REUTERS/ Eduardo Munoz

Angelina Jolie studies the wounds of a burned Iraqi refugee, whose identity is hidden because he is still being hunted by militias who tortured him and left him for dead in Baghdad, in Damascus, Syria on August 27, 2007. REUTERS/UNHCR/Morris Bernard/Handout

Shakira dances with children from the Max Payne Hand in Hand School for Bilingual Education during her visit to the school in Jerusalem June 21, 2011. REUTERS/Ronen Zvulun

Lionel Messi walks on a street during his visit after a major earthquake to Port-au-Prince, Haiti July 15, 2010. REUTERS/Stringer

Angelina Jolie plays with Afghan refugee children during her visit at Kacha Gari refugee camp in Peshawar, Pakistan, May 5, 2005. REUTERS/UNHCR/Handout