The "HIV Transmission in Intimate Partner Relationships in Asia" report by UNAIDS said the women at risk are either married or in long-term relationships with men who engage in "high-risk sexual behaviours."
"That is, men who have sex with men, injecting drug users, the clients of sex workers," UNAIDS regional director Prasada Rao said.
"(It's) a problem of great magnitude that the countries have largely ignored (and) a challenge that we may no longer ignore," Rao told reporters on the sidelines of the ninth International Congress on AIDS in Asia and the Pacific (ICAAP), which is being held on the Indonesian resort island of Bali.
Women accounted for 35 percent of all adult HIV infections in Asia in 2008, up from 17 percent in 1990, according to the report.
In Cambodia, India and Thailand, the largest number of new HIV infections occur among married women and in Indonesia the virus is now spreading to long-term partners and sex workers, it added.
"The facts speak for themselves. It is estimated that more than 90 percent of the 1.7 million women living with HIV in Asia became infected (by) husbands and partners while in long-term relationships," Rao said.
"These women are often perceived as low risk... women who have not been adequately covered in our national responses."
The Bali congress, which runs until Thursday, covers topics ranging from HIV risks among transgenders and migrant workers to biomolecular advances in HIV treatment and the impact of the financial crisis on those with HIV/AIDS.