Britain's Prime Minister Boris Johnson welcomes Gabon's President Ali Bongo Ondimba outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson waits for Gabon's President Ali Bongo Ondimba to arrive outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson waits for Gabon's President Ali Bongo Ondimba to arrive outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson walks out to welcome Gabon's President Ali Bongo Ondimba (not pictured) outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson waits for Gabon's President Ali Bongo Ondimba to arrive outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson walks out to welcome Gabon's President Ali Bongo Ondimba (not pictured) outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson welcomes Gabon's President Ali Bongo Ondimba outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson welcomes Gabon's President Ali Bongo Ondimba outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson waits for Gabon's President Ali Bongo Ondimba to arrive outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson welcomes Gabon's President Ali Bongo Ondimba outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson welcomes Gabon's President Ali Bongo Ondimba outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson welcomes Gabon's President Ali Bongo Ondimba outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Britain's Prime Minister Boris Johnson welcomes Gabon's President Ali Bongo Ondimba outside 10 Downing Street in London, Britain May 20, 2021. REUTERS/Henry Nicholls

Judo - 2021 Kazan Grand Slam judo tournament - Tatneft Arena, Kazan, Russia - May 7, 2021 Gabon's Paul Kibikai. REUTERS/Alexey Nasyrov

Judo - 2021 Kazan Grand Slam judo tournament - Tatneft Arena, Kazan, Russia - May 7, 2021 Gabon's Sarah-Myriam Mazouz. REUTERS/Alexey Nasyrov

Athletics - World Athletics Championships - Doha 2019 - Men's 200 Metres Heats - Khalifa International Stadium, Doha, Qatar - September 29, 2019 Noah Lyles of the U.S. in action with Canada's Brendon Rodney and Gabon's Guy Maganga Gorra REUTERS/Lucy Nicholson

Gabon's Foreign Minister Alain-Claude Bilie By Nze addresses the 74th session of the United Nations General Assembly at U.N. headquarters in New York City, New York, U.S., September 26, 2019. REUTERS/Eduardo Munoz

Gabon's Foreign Minister Alain-Claude Bilie By Nze addresses the 74th session of the United Nations General Assembly at U.N. headquarters in New York City, New York, U.S., September 26, 2019. REUTERS/Eduardo Munoz

Gabon's president Ali Bongo Ondimba addresses the 72nd United Nations General Assembly at U.N. headquarters in New York, U.S., September 21, 2017. REUTERS/Lucas Jackson

Gabon's President Ali Bongo Ondimba shakes hands with China's President Xi Jinping before their bilateral meeting at the Great Hall of the People in Beijing, China September 1, 2018. Nicolas Asfouri/Pool via REUTERS

Gabon's President Ali Bongo Ondimba shakes hands with China's President Xi Jinping before their bilateral meeting at the Great Hall of the People in Beijing, China September 1, 2018. Nicolas Asfouri/Pool via REUTERS

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Abdallah El Said of Egypt's Al Ahly celebrates his goal. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - An Egypt's Al Ahly fan shouts slogans against the Interior Ministry whilst running with a flare during the game. REUTERS/Mohamed Abd El Ghany TPX IMAGES OF THE DAY

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Plain clothes police officers react during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Egypt's plain clothes policemen arrest fans of Egypt's team Al Ahly during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Egypt's Al Ahly fans shout slogans against the Interior Ministry and throw seats towards police during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Egypt's Al Ahly fans shout slogans against the Interior Ministry and throw seats towards police during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Egypt's Al Ahly fans shout slogans against the Interior Ministry and throw seats towards police during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Egypt's plain clothes policemen arrest fans of Egypt's team of Al Ahly during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - An Egypt's Al Ahly fan shouts slogans against the Interior Ministry whilst running with a flare during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Egypt's Al Ahly fans shout slogans against the Interior Ministry whilst holding flares during the game. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Al Ahly's Abdallah Said in action with CF Mounana's David Massamba. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Al Ahli's Marwan Mohsen in action with CF Mounana's Ralph Bamba. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Al Ahly coach Hossam El-Badry gestures. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 - Al Ahli's Hossam Ashour in action with CF Mounana's Karl Mboudou. REUTERS/Mohamed Abd El Ghany

Football Soccer - CAF African Champions League - Egypt's Al Ahly v Gabon's CF Mounana - Cairo International Stadium, Cairo, Egypt - March 6, 2018 Fans of Egypt's Al Ahly cheer before the start of the game. REUTERS/Mohamed Abd El Ghany

Gabon's President Ali Bongo Ondimba addresses a meeting on climate change at the 30th Ordinary Session of the Assembly of the Heads of State and the Government of the African Union in Addis Ababa, Ethiopia January 29, 2018. REUTERS/Tiksa Negeri

Gabon's President Ali Bongo Ondimba addresses a meeting on climate change at the 30th Ordinary Session of the Assembly of the Heads of State and the Government of the African Union in Addis Ababa, Ethiopia January 29, 2018. REUTERS/Tiksa Negeri

Gabon's President Ali Bongo Ondimba arrives for the 30th Ordinary Session of the Assembly of the Heads of State and the Government of the African Union in Addis Ababa, Ethiopia January 29, 2018. REUTERS/Tiksa Negeri

Gabon's President Ali Bongo Ondimba, Cameroon's President Paul Biya, France's President Emmanuel Macron and King of Morocco Mohammed VI talk while they prepare to pose for photographers during the 5th African Union - European Union (AU-EU) summit in Abidjan, Ivory Coast November 29, 2017. REUTERS/Luc Gnago

French President Emmanuel Macron speaks with Moroccan King Mohammed VI, while President of Gabon Ali Bongo Ondimba and Cameroon's President Paul Biya stand near, as leaders gather for the family photo at the 5th African Union - European Union (AU-EU) summit in Abidjan, Ivory Coast, November 29, 2017. REUTERS/Philippe Wojazer

French President Emmanuel Macron speaks with Moroccan King Mohammed VI, President of Gabon, Ali Bongo Ondimba, and Cameroon's President Paul Biya as leaders gather for the family photo at the 5th African Union - European Union (AU-EU) summit in Abidjan, Ivory Coast, November 29, 2017. REUTERS/Philippe Wojazer

French President Emmanuel Macron shakes hands with the President of Gabon Ali Bongo Ondimba as they attend the opening ceremony for The Africa EU Summit in Abidjan, Ivory Coast, November 29, 2017. REUTERS/Ludovic Marin/Pool

Gambia's Vice President, Fatoumata Tambajang (L) and Gabon President Ali Bongo Ondimba attend the opening ceremony of the 5th African Union - European Union (AU-EU) summit in Abidjan, Ivory Coast November 29, 2017. REUTERS/Luc Gnago

Gabon's president Ali Bongo Ondimba waits to address the 72nd United Nations General Assembly at U.N. headquarters in New York, U.S., September 21, 2017. REUTERS/Lucas Jackson

Gabon's president Ali Bongo Ondimba addresses the 72nd United Nations General Assembly at U.N. headquarters in New York, U.S., September 21, 2017. REUTERS/Lucas Jackson

FILE PHOTO: Football Soccer - African Cup of Nations - Semi Finals - Burkina Faso v Egypt- Stade de l'Amitie - Libreville, Gabon - February 1, 2017. Egypt's Mohamed Salah celebrates after the game Reuters / Amr Abdallah Dalsh Livepic / File Photo

President of Gabon, Ali Bongo Ondimba, arrives to speak at the opening of The Ocean Conference at the United Nations in the Manhattan borough of New York City, New York, U.S. June 5, 2017. REUTERS/Carlo Allegri

President of Gabon, Ali Bongo Ondimba, speaks at the opening of The Ocean Conference at the United Nations in the Manhattan borough of New York City, New York, U.S. June 5, 2017. REUTERS/Carlo Allegri

The headquarters of Total’s Gabon operations in Libreville, Gabon March 22, 2017. Picture taken March 22, 2017. REUTERS/Gerauds Wilfried Obangome

Visitors walk along a beach in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

Visitors walk along a beach in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

A woman sells dried fish fish at a market in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

An OiLibya petrol station is seen in front of an outlet of French retail group Geant in Libreville, Gabon February 2, 2017. REUTERS/Mike Hutchings

A woman buys vegetables at a market in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

Visitors walk along a beach in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

A man sells fish at a market in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

Cars drive past a billboard for telecommunications company Gabon Telecom in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

A man walks past a billboard for telecommunications company Gabon Telecom in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings

An outlet of French retail group Geant is seen in Libreville, Gabon, February 2, 2017. REUTERS/Mike Hutchings