Buhari made the comment on Thursday, December 1, during a meeting with United States Ambassador to Nigeria, William Stuart Symington.

“The corruption we met at personal and institutional levels was unbelievable. Corruption was turning into a culture. After we came in, people started realizing the truth,” Buhari said.

“When I was invited to the G-7 meeting after my inauguration on May 29, 2015, I thought I was going to be an observer at the meeting, but without prompting, I was asked to brief the leaders on the security situation in Nigeria, and I did. Since then, we have received support in training and military hardware, and I hope we have not disappointed,” he added.

Symington met with Buhari at the Presidential Villa in Abuja when he went to submit his Letter of Credence.

ALSO READ: 'Nigerians won't abandon Buhari in 2019,' Presidency replies Galadima

A letter of credence is an official document conveying the credentials of a diplomatic envoy to a foreign government.