The director of the U.N. AIDS program has marked World AIDS Day Thursday, by urging the international community to do all it can to fight the deadly disease.

Dr. Peter Piot, the Executive Director of U.N. AIDS, said the latest global figures show signs of hope, with adult infection rates decreasing in a few nations, notably Kenya and Zimbabwe and some Caribbean countries.

He said, however, the number of people living with AIDS worldwide has reached its highest level ever - with more than 40 million people infected, nearly half of them women.

He said comprehensive prevention, treatment and care programs need to be increased on a massive scale to help reverse the spread of HIV/AIDS.

The United Nations has launched a five-year campaign under the theme "Stop AIDS. Keep the Promise," to encourage governments to meet their commitments to fight the disease.