World leaders gathering in London have been urged to cancel drought-hit Somalia's debt as millions of people in the African country face starvation.
Famine has already gripped South Sudan, with hunger killing many there and in Somalia, while a national emergency has been declared in Kenya and there are fears of a new wave of drought in Ethiopia.
Aid agencies say the threat of starvation is unprecedented, with millions at risk and a very real concern that tens - perhaps hundreds - of thousands could die.
Following initial discussions Theresa May reaffirmed Britain's commitment to delivering £10 million over the next two years for emergency food assistance, lifesaving nutrition, safe drinking water and emergency healthcare and pledged an additional £21 million in aid to support the training of a national army in Somalia.
She said: "Our commitment to Somalia matters, not just because it's right to help Somalia overcome the threat of terrorism and the devastating effects of years of famine and bloodshed, but also because these challenges that face Somalia affect us all."
Save the Children CEO Kevin Watkins warned that "early and decisive action" was needed to halt the loss of life in the East African country.
He said: "Somalia continues to drift towards an avoidable famine.
"Without early and decisive action to support and tackle the desperate nutrition, health and water needs of vulnerable communities, more children will become severely malnourished - and lives will be lost."
He added: "Restoring Somalia's relations with the World Bank, cancelling the country's debt, and providing immediate financial support from the World Bank's international development association facility is critical."
Prime Minister Theresa May is hosting a high-level conference in London on Thursday to consider the humanitarian crisis and security situation in Somalia.
The summit at Lancaster House will be addressed by Mrs May, Foreign Secretary Boris Johnson and International Development Secretary Priti Patel.
The focus of the meeting will be the agreement of a security pact and the reforms needed to support the country over the next four years.
ITV News International Affairs Editor Rageh Omaar previews the key themes at the heart of the conference:
The UK Government will reaffirm its commitment to preventing a famine, and call on the international community to urgently step up their support.
The declaration of famine in South Sudan in February and the imminent threat of starvation in Somalia, Ethiopia and Kenya triggered the launch of the Disasters Emergency Committee (DEC) East Africa Crisis Appeal, which has raised more than £55 million since March.
DEC boss Saleh Saeed said: "We hope that this conference will result in much-needed progress for Somalia helping build resilience - at national, local and individual level - so that the country can withstand future humanitarian emergencies.
"More funding is urgently needed to address the crisis and we hope that the conference will result in increased humanitarian finance."
Action Aid's head of humanitarian response Mike Noyes said: "Drought has pushed millions of Somalis to the brink of starvation."
"Despite UK generosity, the UN emergency appeal for Somalia remains chronically underfunded.
"The London Somalia conference is a huge opportunity to galvanise international humanitarian support."