Bill Clinton has called on the US government to provide better funding programmes to tackle HIV and Aids.

The former president said the US was not paying its fair share to the global fund to fight Aids, TB and Malaria.

The difference of where we are and where we need to be is less than two months of the war in Afghanistan

Bill Clinton

However, he warned that no government could afford to write out a blank cheque.

Mr Clinton, who is the co-chairman of the International Aids Trust, described the Aids epidemic as the biggest single problem for the world, barring nuclear war.

The US gives more money to the Global Fund than any other country. But critics argue that's it is still too little when viewed as a proportion of America's wealth.

Mr Clinton said the best way to improve the situation was for countries to appeal to the US to fund specific projects.

These were more likely to be viewed sympathetically by American politicians than demands for huge sums of money without guarantees they would be well spent, he said.

"America now spends $800m a year on fighting the Aids epidemic world-wide, and our fair share would be $2.5bn.

"The difference of where we are and where we need to be is less than two months of the war in Afghanistan."

Mr Clinton embraced two women with HIV

Mr Clinton, who addressed the International Aids Conference in Barcelona, stressed all nations must do more to combat HIV.

He said: "For the first time in history the world has to take responsibility for a global health crisis."

Although the problem was most acute in Africa, it was spreading quickly in Asia and Caribbean, and threatened to explode in India, Mr Clinton said.

He suggested the Indian government might be in denial about the scale of the problem it faced.

Funding shortfall

Rupert Everett called for more compassion

Less than a third of the estimated $10 bn needed annually to provide life-saving drugs to poor nations has been pledged to the Global Fund to fight Aids, Tuberculosis and Malaria.

Mr Clinton said: "It is important that every government has a plan.

"We know you need more money, but I would argue that you will get more money if you have a specific plan to spend the money."

Mr Clinton, who was addressing a youth forum at the conference, fielded questions of topics ranging from the stigma of HIV to poverty and religion.

At the same conference, actor Rupert Everett rounded on the Catholic Church for failing to sanction the use of condoms, which experts say is essential if the spread of HIV is to be checked.

Mr Everett said: "Where is the Christian compassion for this human condition? There is no middle way with the Catholic Church, but celibacy hasn�t worked for the priesthood, after all.

"We have to change men's attitudes on using condoms - it is manly to protect your partner and yourself."