Foreign Secretary Boris Johnson has called for a major boost in trade with Nigeria during a visit to the west African country.
Mr Johnson met British military personnel in the capital Lagos who are helping the Nigerian government to combat pirates.
More than 120 pirate attacks were reported in the Gulf of Guinea last year, costing around £619 million.
The gulf is targeted because more than £6 billion of west African trade with the UK, and around 15% of oil imported to Britain, moves through the area annually.
Mr Johnson said: "Nigeria is a country of huge promise and big ambitions. British businesses such as Diageo and Unilever are thriving here and I want to see even more British companies succeeding in Nigeria, and more Nigerian companies in Britain.
"The potential of Nigeria's markets, people and natural resources is enormous and helping to secure a prosperous future for our two countries is a key part of our Commonwealth heads of government meeting next year.
"Our military links are close and longstanding. British military training is helping Nigeria to take on Boko Haram and to fight back against piracy in the Gulf of Guinea.
"This close military co-operation is the cornerstone of our joint efforts to defeat terror and to create the conditions for peace, stability and prosperity."
Mr Johnson, on a joint visit to the country with International Development Secretary Priti Patel, also formally dedicated a new Commonwealth war memorial at the National Military Cemetery.