VIENNA (AP) -- Rich countries must give more for the fight against AIDS or risk jeopardizing progress in battling the disease, participants at an international conference urged Thursday.

At issue is the replenishment of the Global Fund to Fight AIDS, Tuberculosis and Malaria, which provides major support for AIDS programs around the world.

Donors meet in October to decide on the fund's financing level for the next three years amid concerns that a desired $20 billion in pledges won't be reached. The matter has overshadowed the AIDS 2010 conference in Vienna, the Austrian capital, attended by thousands of experts and advocates.

"This is not the time to withdraw resources from AIDS," said Nicci Stein, director of the Canadian-based Interagency Coalition on AIDS and Development. "We risk losing the investments made to date and we will be betraying those communities who for the first time have real hope for the future."

Michel Kazatchkine, executive director of the Global Fund, underscored that much was at stake.

"I certainly agree with the fact that a lot of the progress that we have made could indeed be lost," he told The Associated Press. "I know there is an economic crisis but then I'm saying this is a political decision and politics is about choices and where you put your priorities."

Programs financed by the Global Fund were providing antiretroviral treatment to 2.5 million people at the end of 2009.

Stein and other activists from a range of countries and civil society groups warned that underfunding would be particularly problematic for sub-Saharan Africa.

To make their point, they issued report cards for 13 rich countries. Austria, the host of the conference, did the worst and got an "F" for giving just $1.1 million to the fund since its inception in 2002. The country has been criticized by delegates -- and speakers -- for days over its inaction.

Kazatchkine said he was surprised by Austria's stance, articulated in a very strongly worded recent letter, adding he planned to personally write to President Heinz Fischer about the matter.

He said the Global Fund is not based on theoretical needs but rather responds directly to requests by countries who have to specify how they will spend the money.

"If I look retrospectively at the last seven years, 85 percent of the targets have been achieved," he said.

Earlier this week, the World Health Organization announced that the number of people taking crucial AIDS drugs climbed by a record 1.2 million last year to 5.2 million overall. Between 2003 and 2010, the number of patients receiving lifesaving antiretroviral treatment increased twelve-fold, according to the Geneva-based body.

To Joyce Kamwana, a woman from Malawi who is HIV positive, medication provided through the Global Fund made it possible for her to take care of her daughters and live to become a grandmother.

"To me personally, the Global Fund is my lifeline," Kamwana said.

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