Tony Blair has urged the Sudanese government to end the slaughter in the Darfur region and ease the humanitarian crisis which has cost 50,000 lives.
In talks with President Omar Ahmed al-Bashir and his deputy in Khartoum, the UK prime minister asked Sudan to adopt a five point plan to end the crisis.
Mr Blair also urged Sudan to give aid groups access to 1.4m refugees and a fuller role to African peacekeepers.
He is visiting Khartoum on the first leg of a three-day trip to Africa.
Five point plan for the Sudanese
Allow in more African Union peacekeepers
Identify own troops and sponsored militias to aid monitoring
Reach agreement with rebels
Reach agreement on ethnic tensions throughout country
Commit to helping humanitarian aid through to those in need
During the talks, Mr Blair coupled his message with a new £100m aid package for the country next year.
But he also pressed home the international community's concern over the Darfur conflict.
"We can't have a situation where thousands of people are dying, and nothing is done," he said.
The United Nations World Food Programme say they are now feeding more than 1.3m people a month in Darfur.
It was important that people in Darfur realised the international community was determined to ensure the government of Sudan realised its responsibilities, he said.
The rebel forces must also recognise their responsibilities, he added.
"The international focus will not go away while this situation remains outstanding."
The meeting comes a day after the UN special envoy to Sudan Jan Pronk called for a beefed up Africa Union peacekeeping force to be deployed.
International Development Secretary Hilary Benn is accompanying Mr Blair on the trip which is the first of a UK prime minister to the country for 50 years.
The conflict in the remote western region involving a government-backed militia known as the Janjaweed has been declared genocide by the US government and has led to 1.4m people being displaced.
Liberal Democrat foreign affairs spokesman Sir Menzies Campbell said Mr Blair's backing for the planned expansion of the African Union's peacekeeping force in Darfur to 3,500 troops was not enough "to deal with the unfolding catastrophe".
"Thousands more troops are needed, and they should be given an express UN mandate to use force to protect civilians.
"Aid agencies report there has been no improvement in Darfur during the past 12 months.
"Unless there is concrete progress in the next few days, the British government should initiate limited sanctions against Sudan."
Independent cross-bench peer Lord Alton, who helped set up the Jubilee 2000 Drop the Debt campaign, has just returned from Darfur.
He warned the international community were "sleepwalking" into another Rwanda and urged it to impose oil sanctions and a declare a no fly zone in the region.
Mr Blair will fly to the Ethiopian capital Addis Ababa later where he will hold talks with Prime Minister Meles Zenawi.
On Thursday he is due to chair a session of his Africa taskforce, the Commission for Africa.
Mr Blair launched the commission in February 2004 to assess the African situation and draw up future policies after calling Africa's problems a "scar on the world's conscience".
The Ethiopian talks will also be attended by Band Aid organiser Bob Geldof, 20 years after his appeal to help people starving there raised £90m.
The commission is scheduled to report its findings in time for them to be discussed by the G8, when the UK takes over its presidency next year.
Mr Blair has promised to make the plight of Africa one of the twin focuses of his G8 chairmanship, along with climate change.
The commission session, starting on Thursday, will be "workmanlike" and assess progress made so far, Mr Blair's spokesman said.
"It's important that Africa sees this report has been produced with Africa rather than for Africa and that's why it's important we meet in Ethiopia.
The key was helping "Africa help itself" but there were no "instant solutions", the spokesman added.