London is the site of an international meeting Thursday for Somalia.
British Prime Minister David Cameron told the BBC that al-Shabaab remained a key threat to the war-torn country.
"It is based on the fact that al-Shabaab is an organization that has now explicitly linked itself to al-Qaida, and it encourages violent jihad not just in Somalia but also outside Somalia," Cameron said.
Al-Shabaab controls parts of southern and central Somalia, though it's lost ground in part due to the increased presence of African troops in the region.
Somalia won praise from the United Nations recently for moving closer to ending the tenure of the transitional government. Human Rights Watch countered, however, that issues like the use of child soldiers were problems for the country.
The U.N. General Assembly this week passed a resolution to increase the African Union force in Somalia from 12,000 to 17,700 soldiers. The BBC notes the aim of the resolution is to diminish the military capacity of al-Shabaab.
CNN reports Wednesday that Ethiopian forces took control of the southern Somali town of Baidoa from al-Shabaab.