David Cameron is to appeal to international leaders to step up support for Somalia in an effort to stabilise the country described as "the world's most failed state".
Representatives of more than 50 countries are gathering in London for a high level international conference amid fears the east African nation is becoming the new breeding ground for international terrorism.
Mr Cameron said he wanted to "forge a new momentum" and put in place the "building blocks" to create a stronger and safer Somalia after two decades blighted by war, piracy, terrorism and famine.
Among the senior figures attending will be United Nations Secretary General Ban Ki-moon, US Secretary of State Hillary Clinton as well as the leaders of neighbouring African states.
Hopes for progress have risen in recent months after troops from the African Union force in the country (Amisom) succeeded in driving the Islamist al Shabaab group from the capital Mogadishu.
They were further bolstered by reports that the al Shabaab stronghold of Baidoa in the south west of the country has fallen to troops from neighbouring Ethiopia and Somali government forces.
The UN Security Council on Tuesday voted unanimously to increase the Amisom presence from 12,000 troops to 17,700 while increasing funding and expanding its area of operations.
Nevertheless al Shabaab remains in control of much of the country and earlier this month it underscored its commitment to violent extremism by publicly declaring its affiliation to al Qaida.
A recent report by the Royal United Services Institute thinktank estimated that there were currently around 200 foreign fighters in training camps in the country - with around a quarter of them coming from Britain.
The report echoed a warning made by MI5 director general Jonathan Evans in 2010 that it was "only a matter of time" before there were terrorist attacks on the streets of Britain inspired by those fighting in Somalia. With the London Olympics later this year, Mr Cameron has acknowledged that the security threat from al Shabaab was "real" and "substantial".