Kenya's President Mwai Kibaki has rejected suggestions that he has lost the political will to fight corruption.
Donors restored aid after Mwai Kibaki came to power
"There should be no doubt in anybody's mind about our commitment to winning the fight against graft," he said.
These were his first comments since fresh allegations were made about the scale of corruption and the resignation of his chief anti-graft adviser.
Mr Kibaki was elected in 2002 on a pledge to clean up Kenya, but diplomats say "massive looting" continues.
"We recognise that this fight [against corruption] is vital for the performance of the economy and improvement of the welfare of Kenyans," he said.
"It is therefore a war we are determined to win."
Mr Kibaki did not, however, mention the latest allegations directly, or the resignation of anti-corruption adviser John Githongo.
On Thursday, the president ordered an inquiry into corruption.
An audit of the security contract bidding process was launched last year after protests over a $34m deal given to a French firm.
The report has revealed details about how contracts are awarded, that Mr Kibaki says must be examined.
Two ministers have threatened to resign and Vice-President Moody Awori admits there is "massive corruption" at senior levels.
The US has already suspended funding to Kenya and the EU has warned that corruption must be tackled.
Mr Kibaki said the audit had raised questions, and told Kenya's anti-corruption commission "to move with speed and act appropriately... to ensure there is no loss of government funds".
Health Minister Charity Ngilu said that if corrupt ministers did not leave, the entire cabinet should be sacked.
John Githongo has not spoken publicly about his resignation
First Planning Minister Peter Anyang' Nyong'o backed her call.
"The president must take decisive action to save the government and the country from this ignominy," he said.
Most donors cut off aid under former President Daniel arap Moi, citing corruption. They restored funding under Mr Kibaki.
Last week, UK High Commissioner to Kenya Sir Edward Clay said "massive looting" was continuing and that he knew of at least 20 dubious public contracts.
But Justice Minister Kiraitu Murungi warned diplomats not to behave as "local partisan political activists".
In apparent reference to Mr Githongo, he said: "We cannot fight corruption by running away."
A Transparency International survey of perceived corruption rated Kenya 122nd out of 133 countries in 2003.