Africa has experienced seven coups since August 2020, before the one on Wednesday in Gabon. Others are Niger, Sudan, Burkina Faso, Mali, Guinea, and Chad.
The ministry said maintaining normal diplomatic ties with the West African country would become more difficult.
Mr Nguema was named transition leader by Gabon Junta shortly after Mr Bongo’s government was toppled on Wednesday.
“My fear has been confirmed in Gabon that copycats will start doing the same thing until it is stopped,” said Mr Tinubu.
The ministry said that it was “constantly assessing the security and operating conditions of our embassy.”
A building in central Johannesburg, South Africa, gutted by fire, has killed at least 73 people and injured 52 others.
According to local media reports in Gabon, Mr Nguema was Mr Bongo’s cousin.
The sweeping changes in Cameroon and Rwanda came barely hours after the coup in Gabon, where President Ali Bongo Ondimba was toppled and placed under house arrest.
Mr António, who arrived in Abuja on Tuesday, delivered the message from Mr Lourenço to Mr Tinubu.
The military coup came minutes after the state election body declared the winner of Saturday’s general election.
