Image caption In India, the rate of new HIV infections fell by more than 50%, according to UNAids

UN Secretary General Ban Ki-moon has called for global action to end the Aids disease by 2020.

"That is our goal - zero new infections, zero stigma and zero Aids-related deaths," Mr Ban said at a UN summit on Aids in New York.

The three-day meeting marks the 30th anniversary since the discovery of HIV - the virus that leads to Aids.

Meanwhile, African leaders called for greater resources to battle the pandemic across the world.

Some 34m people have Aids, but about half of them do not know they have the disease, according to the UN.

'Insufficient funds'

"Today, we gather to end Aids," Mr Ban said at the opening of the United Nations General Assembly meeting on Wednesday.

"If we are to relegate Aids to the history books we must be bold. That means facing sensitive issues, including men who have sex with men, drug users and the sex trade," the UN chief said.

30 years of HIV 5 June 1981: Center for Disease Control mentions a new virus in its weekly mortality report

Center for Disease Control mentions a new virus in its weekly mortality report 1982: The term Aids (acquired immunodeficiency syndrome) first used

The term Aids (acquired immunodeficiency syndrome) first used 1984: Virus identified and named HIV

Virus identified and named HIV 1985: Rock Hudson dies of Aids, teenage haemophiliac Ryan White expelled from school because infected through treatment

Rock Hudson dies of Aids, teenage haemophiliac Ryan White expelled from school because infected through treatment 1987: First showing of Aids Memorial Quilt on National Mall in Washington DC

First showing of Aids Memorial Quilt on National Mall in Washington DC 1991: Jeremy Irons wears red ribbon and basketball's Magic Johnson has the virus

Jeremy Irons wears red ribbon and basketball's Magic Johnson has the virus 1993: Philadelphia film wins two Oscars

Philadelphia film wins two Oscars 2000: Infection rate in US among African Americans overtakes that in gay men

Infection rate in US among African Americans overtakes that in gay men 2011: Global death toll 22m, infections 60m Audio slideshow: Living with HIV How a red ribbon conquered the world 'More money needed' for HIV cure

Mr Ban stressed that new infections have dropped by 20% since 2001 - the year when world leaders first pledged to act to control the pandemic.

He also urged the global community to "come together in global solidarity as never before" to achieve universal access to Aids treatment by 2015 and also efforts to lower costs.

The meeting is being attended by 30 presidents and heads of government, and some of the African leaders spoke of the desperate need for more funds to fight the disease.

"To say that adequate funding is critical to the success of our HIV and Aids response is an understatement," said Nigerian President Goodluck Jonathan, whose country has the highest number of HIV-positive people after South Africa.

Gabon's President Ali Bongo Ondimba said that resources available for Africa "remain insufficient given the size of the HIV/Aids impact on the continent".

More than 9m people still do not get retroviral treatment to keep HIV/Aids at bay, and an estimated 1.8m people die each year from Aids.