JOHANNESBURG (AP) — Civil society organizations in South Africa said Wednesday that adolescent girls and women are among the first vulnerable groups to feel the pinch of U.S. foreign aid cuts as the Trump administration phases out its more than $400 million support annually for the country's HIV programs.

The U.S. State Department has said that it would "begin a phased drawdown" of the President's Emergency Plan for AIDS Relief, or PEPFAR, a program that has supported South Africa's battle against HIV and AIDS for the last 20 years and is widely credited with saving more than 20 million lives over that period.

READ MORE: Vulnerable South Africans struggle to find HIV medication after U.S. foreign aid cuts

The phasing out of most programs is expected to be completed by the end of September, with critical personnel support continuing through March next year, according to the U.S. State Department.

South Africa has the highest number of people living with HIV, with approximately 8 million people, or about 12.7 % of its 63 million population.