Australian Prime Minister Tony Abbott.
Bahamas' Prime Minister Perry Christie.
Bangladesh's President Abdul Hamid.
Belgian Prime Minister Elio di Rupo and King Philippe.
Benin's President Boni Yayi.
Botswana's President Seretse Ian Khama.
Brazilian President Dilma Rousseff and three of her predecessors, including Luiz Inacio Lula da Silva.
British Prime Minister David Cameron, deputy Prime Minister Nick Clegg and former Prime Minister Tony Blair.
Burundi's President Pierre Nkurunziza.
Canadian Prime Minister Stephen Harper and three of his predecessors.
Chadian President Idriss Deby.
Chinese Vice President Li Yuanchao.
Comoros' President Ikiliou Dhoinine.
Congo's President Joseph Kabila.
Croatian President Ivo Josipovic.
Cuban President Raul Castro.
Czech Foreign Minister Jan Kohout.
Danish Prime Minister Helle Thorning-Schmidt and Prince Frederik.
Djibouti's President Ismail Omar Guelleh.
East Timor's Prime Minister Xanana Gusmao.
El Salvador's Foreign Minister Jaime Miranda.
Equatorial Guinea's President Obiang Nguema Mbasogo.
Ethiopia's Prime Minister Hailemariam Desalegn.
European Commission President Jose Manuel Barroso.
European Union Council President Herman Van Rompuy.
Finnish President Sauli Niinisto.
French President Francois Hollande and his predecessor Nicolas Sarkozy.
Gabon's President Ali Bongo Ondimba.
Gambian President Yahya Jammeh.
German President Joachim Gauck.
Ghana's President John Dramani Mahama.
Guinean President Alpha Conde.
Guyana's President Donald Ramotar.
Haitian President Michel Martelly and Prime Minister Laurent Lamothe.
Indian President Pranab Mukherjee and Congress party leader Sonia Ghandi.
Irish President Michael Higgins.
Italian Prime Minister Enrico Letta.
Ivory Coast's President Allasane Ouattara.
Jamaica's Prime Minister Portia Simpson Miller.
Japan's Crown Prince Naruhito and former Prime Minister Yasuo Fukuda.
Jordanian Queen Rania and Prime Minister Abdullah Ensour.
Kenyan President Uhuru Kenyatta.
Lebanese caretaker Prime Minister Najib Mikati.
Lesotho's Prime Minister Thomas Thabane.
Liberian President Ellen Johnson Sirleaf.
Malawi's President Joyce Banda.
Malaysian Energy Minister Maximus Ongkili.
Mauritius' Prime Minister Mohamed Ould Abdel Aziz.
Mexican President Pena Nieto.
Morocco's Prince Moulay Rachid.
Mozambique's President Armando Emilio Guebuza.
Namibian President Hifikepunye Pohamba.
Nepalese Foreign Minister Madhav Prassad Ghimire.
The Netherlands' Foreign Minister Frans Timmermans and King Willem-Alexander.
New Zelands's Prime Minister John Key.
Niger's President Mahamadou Issoufou.
Nigerian President Goodluck Jonathan.
Norwegian Prime Minister Erna Solberg and Crown Prince Haakon.
Pakistan's President Mamnoon Hussain.
Palestinian President Mahmoud Abbas.
Philippines' Vice President Jejomar Binay.
Polish Foreign Minister Radek Sikorski.
Portuguese President Cavaco Silva.
Saudi-Arabia's Deputy Prime Minister Muqrin bin Abdulaziz Al Saud.
Senegalese President Macky Sall.
Serbian President Tomislav Nicolic.
Seychelles President James Michel.
Slovak Foreign Minister Miroslav Lajcak.
Slovenia's President Borut Pahor.
South Korean Prime Minister Hongwon Chung.
South Sudan's President Salva Kir Mayardi.
Spanish Prime Minister Mariano Rajoy and Prince Felipe.
Sri Lanka's President Mahinda Rajapaksa.
Sudanese Vice President Bakri Hassan Salih.
Suriname's President Desire Delan Bouterse.
Swaziland's Prime Minister Sibusiso Barnabas Dlamini.
Swedish Prime Minister Fredrik Reinfeldt and Princess Victoria.
Swiss President Ulrich Maurer.
Tanzanian President Jakaya Kikwete.
Trinidad and Tobago's Prime Minister Kamla Persad-Bissessar.
Tunisian President Moncef Marzouki.
Ugandan President Yoweri Museveni.
U.N. Human Rights Commissioner Navi Pillay.
U.N. Secretary General Ban Ki-moon and his predecessor Kofi Annan.
U.S. President Barack Obama and first lady Michelle Obama as well as former presidents George W. Bush, Jimmy Carter, Bill Clinton and his wife Hillary.
Uruguay's Foreign Minister Luis Almagro.
Vatican official Cardinal Peter Turkson of Ghana.
Venezuela's President Nicolas Maduro.
Zambia's President Michael Sata.
Zimbabwean President Robert Mugabe.