President Barack Obama and Secretary of State Hillary Clinton pledged to increase US support in the global fight against HIV and AIDS.

In a video-linked address to experts and advocates gathered in Vienna for the closing session of an international AIDS conference, Obama and Clinton said they will take the lead in ensuring a broad, sustainable and effective approach to the global epidemic.

"Ending this pandemic won't be easy, and it won't happen overnight," said Obama who is facing a tough fiscal environment at home.

The activists in the HIV conference criticized Obama’s administration for failing to increase global funding. Obama said the US is committed to continue to helping AIDS health charities and aid workers build on progress.

Obama said he was facing a tough fiscal environment at home but said the United States was committed to helping AIDS health charities and aid workers build on progress.

While some protesters attacked obama’s administration for failing to increase global funding, a recent U.N. report showed that the U.S. was the largest donor of international AIDS assistance in 2009, accounting for more than 58 percent of disbursements by governments.

Through his global health initiative, Obama set $63 billion for health aid program to help fight diseases and build better health systems in poor nations.

Currently 33.4 million people have AIDS and majority of 25 million people who have died since the early 1980s are from the world’s poorest countries in sub-Saharan Africa.

Clinton said access to HIV/AIDS prevention, treatment and care should be "a universal, shared responsibility."

The next international AIDS conference will be held in Washington in 2012.