Chief executives from leading international corporations are calling for an end to restrictions on travelers who are HIV positive.

Two dozen corporate leaders said Sunday the restrictions imposed by 46 countries around the world are both discriminatory and bad for business. They issued their statement as about 25,000 top AIDS researchers, political leaders, diplomats and other stakeholders gathered for the start of the six-day International AIDS Conference in Washington.

The head of clothing manufacturer Levi Strauss, Chip Bergh, said that in a competitive business world, corporations need to be able to send their personnel everywhere they are needed.

The biennial conference is being held in the United States for the first time in 22 years, after President Barack Obama lifted the U.S. ban on HIV travelers in 2010.

Secretary of State Hillary Clinton, former President Bill Clinton and former first lady Laura Bush will speak at the conference. Other high-level speakers include World Bank President Jim Yong Kim, and Microsoft chairman and philanthropist Bill Gates.

HIV (human immunodeficiency virus) is found in the body fluids of an infected person and is passed from one person to another through blood-to-blood contact, sexual contact, or from a mother to her child during pregnancy or through breast feeding. HIV often leads to AIDS (acquired immune deficiency syndrome), a disease that alters the immune system, making people much more vulnerable to infections and diseases.

The United Nations says 34-million people lived with HIV/AIDS and 1.7 million died from the disease in 2011.