The secretary-general of oil producers' group Opec, Mohammed Sanusi Barkindo, has passed away in Nigeria, his home country.

Sixty-three-year-old Barkindo was due to step down at the end of July, after six years in the top job at the group.

He died hours after meeting Nigeria's President Muhammadu Buhari, and delivering the keynote address at an energy industry conference in Abuja.

Opec Secretary-General HE Mohammad Sanusi Barkindo passed away yesterday in his home country Nigeria. He was the much-loved leader of the Opec Secretariat and his passing is a profound loss to the entire Opec family, the oil industry and the international community. pic.twitter.com/xYDQvhG0n2

— Opec (@OPECSecretariat) July 6, 2022

Barkindo recently said the oil and gas industry is "under siege" due to years of under-investment, and that allowing trade in oil from Iran and Venezuela could help address the market's current tight supply scenario.

Barkindo's career in the oil and gas industry began in Nigeria in the early 1980s.

He served in various capacities at the Nigerian National Petroleum Corporation (NNPC), and represented Nigeria on Opec's Economic Commission Board.

Barkindo served as Opec’s acting secretary-general in 2006, before returning to the position 10 years later. He led the organisation through a turbulent oil market period, including steering it towards greater cooperation with a group of non-Opec oil producers headed by Russia.

After leaving Opec, Barkindo was due to join the US-based think tank Atlantic Council's Global Energy Centre as a distinguished fellow, the organisation recently announced.