"Financial resources are being committed like never before, people have access to antiretroviral treatment like never before, and several countries are managing to fight the spread like never before," Annan said.
"Now, as the number of infections continues unabated, we need to mobilise like never before."
Continuing the push against the growing epidemic requires "every president and prime minister, every parliamentarian and politician, to declare that 'Aids stops with me'," he said.
This year marks the 19th World Aids Day, the 25th year since the first case of Aids was identified and 10 years since the formation of Unaids, the UN arm formed to fight the virus.
The virus has claimed more than 25 million and infected 40 million more and the virus continues to grow despite international efforts to fight the epidemic
Send us you views
Citing this year's World Aids Day theme of "accountability", Annan said politicians should protect vulnerable groups, including sex workers and people living with HIV.
He also said they need "to work for real, positive change that will give more power and confidence to women and girls, and transform relations between women and men at all levels of society."
Rates of HIV/Aids infection continue to grow, with four million new cases worldwide every year. The battle is being waged even in countries that were previously models of control.
The world will miss the Unaids 2010 target of treating 9.8 million people with antiretrovirals by more than half, according to the International Treatment Preparedness Coalition.
|"We have a very long way to go still in the provision of medicines to those who need them,"|
Anders Nordstrom, WHO's Director-General
Annual investments in the response to Aids in low- and middle-income countries now stand at more than $8 billion, but Annan speculated in an earlier statement that by 2010 total need will exceed $20 billion annually.
Still, he remained resolute about the UN meeting its goals to fight the virus, which including halting and starting to reverse the Aids epidemic by 2015.
In his message, Anders Nordstrom, the WHO's acting director-general, said that tackling the Aids epidemic remained one of the world's most pressing public health challenges.
Only 1.6 million people or 24 per cent of the 6.8 million people worldwide who need the life-extending therapy receive it, according to the latest joint report of Unaids and the WHO.
He said: "We have a very long way to go still in the provision of medicines to those who need them.
"HIV surveillance remains weak in almost all regions, particularly among marginalised groups. Those at highest risk are not reliably reached through HIV prevention and treatment strategies."
People most at risk of exposure to the deadly virus do not always know how to protect themselves and often lack access to condoms, clean needles and syringes, said Nordstrom.
"Even in countries where the epidemic has a very high impact, such as Swaziland and South Africa, a large proportion of the population do not believe they are at risk."