Health campaigners have hit out at the level of donations to the Global Fund for HIV/Aids, TB and Malaria, saying they fall well short of what is needed.
The fund is designed to help people hit by disease around the world
Around £2.1bn ($3.7bn) has been pledged by countries around the world.
The campaign groups, such as ActionAid and the Global Aids Alliance, say this will be only be enough to sustain current programmes.
They said double that amount was needed to fund new prevention, treatment and care programmes in 2006 and 2007.
The Global Fund replenishment conference was chaired by United Nations Secretary General Kofi Annan and hosted by the Department for International Development in London.
A number of major donors have yet to make firm pledges because of their budget procedures, but are expected to do so.
Another conference will be held in June in 2006 in an attempt to secure additional pledges.
Around six million people around the world die each year from Aids, TB and malaria.
Since it was established in 2002, the Global Fund has supported 300 programmes in 127 countries, offering treatment to around six million people.
'Pressure is key'
Dr Richard Feachem, director of the Global Fund, said: "Today's pledges are a solid step in the right direction, but a lot remains to be done.
"There is a gap and we have to close that gap."
He said he was hopeful they would be able to raise funds for the Global Fund's total needs by 2007.
Hilary Benn, International Development Secretary in the UK, said: "We have a long way yet to go and we need to keep up the pressure if we are going to vanquish these terrible diseases."
"These deaths are largely avoidable and preventable."
The government announced in July that the UK would increase its contributions to the fund from £51m to £100m for both 2006 and 2007.
Kofi Annan said: "The pledges made here today will go a long way towards ensuring the longer term sustainability of the Global Fund.
"They will help countries establish comprehensive programmes to fight Aids, TB and malaria.
"And they will provide us all with an important source of hope and encouragement for the future, hopes that we can make progress in reversing the spread of Aids and other infections diseases."
Felicity Daly of ActionAid, part of the MakePovertyHistory campaign, said: "Where is the urgency among major donors?
"We are disappointed that they have not used this opportunity to take a robust approach to making the G8's historic promise of ensuring universal access to HIV treatment a reality by 2010."
And the US was criticised for pledging just $0.6bn over the next two years, for the first time failing to contribute a third of the money needed by the fund. David Bryden of US based Global Aids Alliance said: "By breaking that promise Bush is letting down the most vulnerable people in the world.
"If his commitment to Africa is real, then words are not enough."