Gavin Williamson in Nairobi, Kenya, last week, thanking troops for their work.
The Defence Secretary has announced that a specialist Army unit will travel to Africa to help tackle sexual violence.
It follows his visits to Kenya, Somalia and Ethiopia, this year.
During Gavin Williamson's visit to Nairobi, he thanked troops for their work, which ranges from delivering infantry training for partner militaries tackling terrorism, to teaching soldiers how to prevent and respond to sexual violence against women.
Kenya is one of many African countries that is locked in battle with Islamist militants.
Al Shabab is thought to have up to 9,000 fighters, who have carried out mass attacks in Kenya, Somalia, and Uganda.
Many of their victims are women, who are sexually assaulted, abused or murdered.
Some women are also recruited as suicide bombers - whether they're willing or not.
Mr Williamson opened a Security Sector and Gender training course at the British Peace and Security Training centre outside Nairobi, where hundreds of personnel from a dozen partner nations will be trained in techniques aimed at preventing and responding to sexual violence against women, men and children in conflict areas.
As well as confirming that a small training team would deploy to East Africa specifically to help tackle sexual violence, he also agreed to an extension of the British Army's infantry training in Kenya.
Defence Secretary Gavin Williamson said:
"A prosperous and secure Africa is firmly in our national interest and our Armed Forces are playing a vital role on the continent.
"Whether fighting for women's rights through our training teams or suppressing terrorist threats, the UK is a nation with a big heart and we are determined to help our partners when they need us.
"The incredible work our service personnel are doing from Somalia to South Sudan will help build a more secure and united continent.
"This will help to set the conditions for trading partnerships across Africa, supporting British and African businesses to create opportunities for everyone."
The Defence Secretary met the President of Somalia, Mohamed Abdullahi Mohamed Farmaajo, to discuss the UK's continued training to tackle gender-based violence and suppressing the Al-Shabaab threat.
Later in Ethiopia, Mr Williamson met UK personnel and representatives of agencies working to combat violence against women, as well as making progress on UK-Ethiopian areas of co-operation in talks with Ethiopia's Defence Minister Motuma Mekassa.