Read MoreGartman keeping an eye on Nigeria
The minister—who was appointed minister of finance in July 2011 and has previously served as foreign minister—stressed that Nigeria itself, rather than foreign countries or pan-governmental organizations, needed to act to combat oil theft.
"We ourselves need to take our own steps to stop those who are involved in participating… there is a kind of a criminal cartel, both domestic and foreign," she said.
Okonjo-Iweala added that the country's oil and gas sector needed to become more transparent and that Nigeria's economy was becoming decreasingly reliant on oil.
"The Nigerian growth story is not going to be about oil. It is going to be about a much more diversified economy. That is what gives me hope," said the minister.
Video: Nigeria could see 'super growth' if corruption ends: Pro
Apart from petroleum, Nigeria's other natural resources include natural gas, tin, iron ore, coal, limestone, niobium, lead, zinc and arable land.