As further aid left the UK to help ease the refugee crisis, Mr Cook answered accusations that Nato had underestimated the response to the air strikes.

Mr Cook said: "We knew to expect there would be ethnic cleansing.

"That is very deeply in President Milosevic's own background - he has been doing it for 10 years.

Robin Cook on BBC News 24: Milosevic has exceeded his greatest crimes

"In the last week he has exceeded even his greatest crimes of ethnic cleansing and ethnic violence.

"But I do not think that any person who is sane, any decent civilised person could have been expect to see that anybody would behave with the barbarity and brutality he has."

Several Sunday newspapers say that Foreign Office officials have privately admitted that the UK and Nato had not foreseen the humanitarian crisis.

But former Irish prime minister John Bruton accused Mr Cook of not telling the truth about the refugee crisis.

Mr Bruton said Mr Cook was "simply not making a truthful statement when he said no-one could have foreseen a refugee crisis on the scale of the one now happening".

He added: "He is wrong. The present refugee crisis was not only foreseeable, it was foreseen. It is profoundly dishonest to pretend otherwise."

Refugee aid

Robin Cook: Holding area for refugees agreed

Mr Cook said that Macedonia had agreed to allow about 100,000 refugees, who had previously been held up at its border, to cross into a Nato-supervised holding area.

Two planes carrying aid to help refugees fleeing from Kosovo left the UK on Sunday.

In addition a Hercules transporter plane left RAF Lyneham, in Wiltshire, for the Albanian capital of Tirana.

It is carrying medical supplies and a six-strong reconnaissance team, which will assess what help is needed in the long term.

Clare Short, the Secretary of State for International Development, is already in Tirana for discussions about the refugee crisis after leaving Heathrow Airport early on Sunday.

Ms Short will discuss the proposals for an international refugee sanctuary inside the Macedonian border.

She is due to meet General Sir Michael Jackson, Commander of the Allied Rapid Reaction Corps.

Disease spreads

Earlier, Ms Short spoke to Kosovar refugees in the National Sports Centre in Tirana, where 800 families are staying.

Short: Assessing long-term aid plans

She also had separate meetings with the Albanian Government and aid agency representatives.

The UK has announced a further £10m of aid for the refugees, on top of £10m already pledged.

Aid already sent out includes a plane carrying 42 tonnes of tents and blankets to Albania to help address the homelessness problem.