Tony Blair will tell the House of Commons on Monday what action the Government has taken to help those areas affected by the Asian tsunami disaster.
The Prime Minister will also use the statement to update MPs on the latest British death toll.
On Friday, Foreign Secretary Jack Straw said that 50 Britons have so far been confirmed dead, whilst a further 391are highly likely to have been killed in the disaster. In addition, officials are still trying to trace 2,000 UK citizens still unaccounted for.
Speaking on BBC1's Breakfast with Frost, Mr Blair said: "Since Jack Straw gave those figures a couple of days ago they haven't moved a great deal, which should give us some hope that we are beginning to reach the peak of the numbers. But we just can't be sure."
"It is just an immensely difficult job to get absolutely accurate figures, all countries are struggling with this," he added.
Mr Blair indicated that the £50 million originally allocated by the Department for International Development in response to the tsunami crisis was now "well on the way" to being spent. He stressed that Britain's exact allocation of aid will not be finalised until the World Bank completes its assessment of need in the countries affected.
Stressing that the problems of Africa will not be overlooked following the tsunami disaster, Mr Blair said that he had a big agenda for the continent as Britain takes up its presidency of the G8 group of leading nations.
"For the first time we have a plan that won't just deal with aid and debt but will also deal on issues of governance within African countries and conflict resolution," he said.
Meanwhile, international development agency, Actionaid said the Prime Minister should make more money available for the tsunami disaster without raiding existing aid budgets.
"It is time for Blair to catch up with the public mood," said Steve Tibbett, Actionaid's head of policy and campaigns.
"The Government holds a contingency fund for emergencies. With 150,000 dead and five million people affected by the tsunami, this is surely a time to use it."