Mr Howard is one of three leaders recognised for their role in fighting terrorism and standing by the United States, said a White House spokeswoman.

The former British prime minister Tony Blair, who also provided troops for the "coalition of the willing" in the invasion of Iraq, is also being honoured, as is the Colombian President, Alvaro Uribe, another close US ally.

"All three leaders have been staunch allies of the United States, particularly in combating terrorism. And their efforts to bring hope and freedom to people around the globe have made their nations, America and the world community [safer]," said the spokeswoman, Dana Perino, on Monday.

Mr Howard agreed that there was a personal warmth between himself and the US President, George Bush, but said the award should be seen in the context of what it means for the friendship between the two nations.

"I am honoured by it, but I see it as a compliment to Australia and the close relationship between our two countries," he told the Herald .

Asked whether the US-Australia relationship had peaked during his tenure, Mr Howard said he believed it had been closer than at any time, but it was not possible to see what lay in the future.

"We had a very strong relationship on trade, intelligence sharing, and military co-operation was definitely stronger than any time in the past," he said.

The Medal of Freedom is the highest civil award in the US. It was first awarded in 1945 and rejuvenated under John Kennedy in 1963. It has been awarded to domestic and foreign political leaders, distinguished soldiers, civil rights activists, actors and sportsmen.

The only other Australian to receive it is Nancy Wake, the spy known as the White Mouse, who served behind enemy lines in World War II.

World leaders who have received the award include the former South African president and apartheid fighter, Nelson Mandela; former Czech Republic president Vaclav Havel, who led the so-called velvet revolution that restored democracy to his nation; and the former German chancellor Helmut Kohl.

But the award of the medal to Mr Howard drew sharp criticism at home from the Greens, who said Mr Howard was "no Nelson Mandela".

"John Howard's record on human rights is blemished, to say the least," said the Greens' Senator Sarah Hanson-Young.

"We're talking about the Australian prime minister who oversaw the locking up of children behind razor wire, who stonily ignored the plight of David Hicks until the 11th hour of a troubled election campaign, who demonstrated an appalling lack of compassion during the Tampa incident, and who disgracefully refused to apologise to the stolen generations," she said.