Mrs Mandara urged federal and state governments to address poverty, ignorance and social inequality.
He said Nigeria should not be exposed to another territorial loss similar to the Bakassi experience.
The UK will sanction institutions that fail to recruit responsibly under new sponsorship rules.
Abuja is missing from the Donald Trump administration’s shortlist of 20 African cities where foreigners seeking to travel to the United States can process visa applications.
He appealed to governments, organisations, and philanthropists to support infrastructure expansion.
China, Indonesia, Iran, Malaysia, Nepal, Nigeria, Sri Lanka, among others, also opposed nuclear weapon sharing and underlined its incompatibility with the NPT.
Mr Leo visited Algeria, Cameroon, Angola, and Equatorial Guinea to strengthen interfaith dialogue.
The Chadian army also confirmed the killing of a significant number of the militants during the attack.
The Pope made the remarks during his visit to Cameroon on Thursday.
It will expand Nigeria’s fibre backbone from about 30,000 kilometres to approximately 120,000 kilometres, connecting all 774 Local Government Areas, the bank said.
