Johannesburg – Theresa May is headed to Africa, her first trip to the continent as British prime minister, with trade-focused stops in South Africa, Nigeria and Kenya as Brexit looms.

"This visit comes at a time of enormous change across Africa with a unique opportunity, as the UK moves towards Brexit, for a truly Global Britain to invest in and work alongside African nations, with mutual benefits," her office said in a statement.

The visit kicks off in Cape Town Tuesday, where May will meet with South African President Cyril Ramaphosa and, weather permitting, go to Robben Island – where South Africa's first democratic leader Nelson Mandela was imprisoned for years by the apartheid regime.

"Strengthening Britain's global partnerships"

She then heads to Nigeria, where she'll meet President Muhammadu Buhari as well as speak to victims of modern slavery.

On the third leg of the trip, in Kenya, she will meet President Uhuru Kenyatta and see British soldiers training troops who will ultimately be sent to fight Al-Shabaab in Somalia.

May will be the first British prime minister to visit former colony Kenya in about 30 years.

"As we prepare to leave the European Union, now is the time for the UK to deepen and strengthen its global partnerships," May said, according to the statement.

"This week I am looking forward to discussing how we can do that alongside Africa to help deliver important investment and jobs as well as continue to work together to maintain stability and security."