Theresa May has signed a security pact with Nigeria’s president aimed at helping the west African nation combat Boko Haram through better military training and anti-terrorist propaganda techniques developed in the UK.

The British prime minister’s agreement with Muhammadu Buhari was announced at a summit between the pair in Abuja and billed by the UK as an example of May’s ambition to promote a greater British presence in Africa and support states under pressure from terrorist threats.

"We are determined to work side by side with Nigeria to help them fight terrorism, reduce conflict and lay the foundations for the future stability and prosperity that will benefit us all,” she said.

Billed as the UK’s first-ever security and defence partnership with Nigeria, the pact was the centrepiece of the second day of May’s three-day trip to Africa, which will see her visit Kenya on Thursday having been to South Africa on Tuesday.

The UK will provide training to the Nigerian military to help it contend with improvised explosive devices used by Boko Haram, and has offered to help train full army units, as opposed to individual soldiers, before they are deployed in the country’s north east, where the Islamist militant group has its base.

It also hopes to cut the flow of new recruits by working with local communities "to push out counter-narratives” to Boko Haram, drawing on the UK’s experience of "countering terrorist propaganda at home” according to pact announcement. An additional £13m will be spent on an education programme for the 100,000 children living in the conflict zone.

May told Buhari that the UK wanted to support Nigeria’s stability and said it was important that their joint work on security was undertaken in line with international standards on human rights. The prime minister added that she endorsed the country’s efforts to combat illegal migration and modern slavery.

The prime minister then travelled to Lagos, where she was greeted with several outdoor hoardings bearing her name. May switched tack to promote Britain’s expertise in financial services while seeking to emphasise future trade possibilities in a week where she had called for the UK to become the leading G7 investor in Africa by 2020.

She met Aliko Dangote, one of the country’s wealthiest men, who has already agreed to list his $10bn cement business on the London Stock Exchange.