Osinbajo said this during the vice-presidential debate organised by the Nigerian Elections Debate Group (NEDG) and the Broadcasting Organisations of Nigeria (BON).
He said this differs from the constitution of other countries.
Asked how taking the job of the vice-president has been since he assumed office over three years, Osinbajo said the demand of the role has since increased his grey hair.
He, however, said despite the herculean nature of his job, it has also been rewarding.
“I am sure that those who know me quite well know that my hair was not this grey when I started out in 2015. So really, it has been tasking,” Osinbajo said.
“And it has also been an incredibly rewarding experience especially looking at it from the point of view of the ability to do the things that one wanted to do all along as an individual.
“The role is one where you are in many senses the chief adviser to the president of the country and possibly the one person that would represent him when when he is absent for a meeting and even when he is absent for a longer period.
“So there is a sense in which the role of the vice president is one that very closely mirrors the role of the president in very profound ways.
“But our vice-presidency is different from that of other countries. Because unlike other countries, even countries that have similar constitutions, our own constitution actually specifies role for the vice president. The vice president is the chairman of the national economic council…that is a constitutional role.
“In some senses, those who say the role of the vice president is like a spare tyre have it wrong because they are probably looking at other jurisdictions. In our jurisdiction, there are specific roles that the vice-president is entitled by law to perform.
“The vice president is also the chairman of the NCP, that is the national council of privatisation , the vice president is also statutory chairman over 22 parastatals and agencies and these are defined by law.
“That role is one that a good degree of trust is required between the president and the vice president. The role of the vice-president is one which also requires, I think, a great deal of patience because you may not always agree with the policies.”