President Obama on Monday pledged up to $5 billion in U.S. money over the next three years to the preeminent global program to combat AIDS on the condition that the rest of the international community pitches in $10 billion.

Obama announced the pledge to the Global Fund to Fight AIDS, Tuberculosis and Malaria as the White House marked World AIDS Day. Donor communities are getting ready to begin meetings in Washington on Monday night to discuss the three-year replenishment cycle of the fund.

The 1-to-2 funding ratio is set by Congress, and Obama had already marked $1.65 billion for the Global Fund in his 2014 budget. But activists — including South Africa's Desmond Tutu — had been pushing Obama to make clear ahead of the conference that the United States stood ready to donate up to $5 billion to the fund for the next cycle.