He insisted the approach remained the one he had set out, despite conflicting statements by Cabinet ministers.

"The objective of the whole operation and strategy is to enable those Kosovo Albanians to return to Kosovo," he said.

Mr Cook said the United Kingdom has already accepted 10,000 Kosovo refugees and would take thousands more.

Robin Cook: "None of them will go back unless they have international security"

He refuted the suggestion Nato's attacks had caused the exodus, instead blaming atrocities carried out by Serbian President Slobodan Milosevic's forces.

"This is not the result of the bombing, this is the result of President Milosevic's ethnic cleansing.

Aid is arriving for the displaced people

"Every single one of them has said they are fleeing from the paramilitary thugs.

"And neither will they go back until they have the international security we are will to provide and President Milosevic will have to accept."

Mr Cook maintained it would have been wrong to have prepared for the flood of refugees as this would have sent the wrong signal to President Milosevic.

"Suppose we had in advance built reception camps for refugees, suppose then the ethnic cleansing had taken place - people would then have said, well you provided him with the incentive."

William Hague: "We need a clear policy on refugees coming to Britain"

His comments came after the UK opposition leader wrote to Prime Minister Tony Blair asking for clarification of the British policy on accepting Kosovan refugees.

Britain has promised to provide emergency shelter to thousands of ethnic Albanians forced to flee from Kosovo.

William Hague: "The refugee operation needs co-ordination"

But it has refused to set a firm figure, while countries including Germany, Turkey, the USA and Australia have detailed how many refugees they will take.

More than 430,000 people have crossed the borders out of Kosovo since the Nato bombardment began on 24 March, according to the United Nations High Commission for Refugees.

Conservative leader William Hague told BBC Radio 4's Today programme a clearer strategy was needed towards the refugees.

"I wrote to the prime yesterday because of the desperate condition of the refugees and the need to do more and have a clearer strategy about it.

"I was really suggesting three things. Most of all, we need a clear command structure, we need a single figure with clear executive authority.

"Secondly, we need a clear policy on refugees coming to Britain. How many are coming to Britain, under what criteria and is it central or local government who are going to support them?

"And, third, I'm putting forward the suggestion that they should match pound for pound the money raised by the aid agencies, which would encourage people to give."

He declined to specify how many refugees he would accept if he was prime minister, but said the government should outline the criteria it would use to decide.

"The refugee operation needs as much co-ordination and command as the military operation.