WASHINGTON (AP) — Federal health officials are recommending an end to the nation's lifetime ban on blood donations from gay and bisexual men, a 31-year-old policy that many medical groups and gay activists say is no longer justified.

The Food and Drug Administration said Tuesday it favors replacing the blanket ban with a new policy barring donations from men who have had man-on-man sex in the previous 12 months. The new policy would put the U.S. in line with other countries including Australia, Japan and the U.K.

Activists, however, questioned whether requiring a year of celibacy from gay men before a donation amounted to a significant policy shift.

The lifetime ban dates from the early years of the AIDS crisis and was intended to protect the blood supply from what was a then little-understood disease. But many medical groups, including the American Medical Association, say the policy is no longer supported by science, given advances in HIV testing. Gay activists say the ban is discriminatory and perpetuates negative stereotypes.

The agency will recommend the switch in draft guidelines early next year and move to finalize them after taking comments from the public, FDA officials told reporters. FDA Deputy Director Dr. Peter Marks declined to give a timeframe for completing the process but said, "we commit to working as quickly as possible on this issue."

Marks said some of the most compelling evidence for changing the policy comes from Australia, which put in place a one-year ban on donations over a decade ago. Recently published studies showed no change in the safety of the blood supply after making the switch.

Additionally, studies conducted by the U.S. government suggest gay and bisexual men are actually more likely to abide by donation guidelines under a 12-month prohibition period. All blood donors take a questionnaire about their health and sexual behavior, but some gay men reportedly answer inaccurately to donate blood.

All U.S. blood donations are screened for HIV but the test only detects the virus after it's been in the bloodstream about 10 days. Still, FDA officials said current research does not support reducing the donation ban below one year.

According to government figures, men who have had sex with other men represent about 2 percent of the U.S. population, yet account for at least 62 percent of all new HIV infections in the U.S.

Despite the shift from federal officials, gay advocates said Tuesday that requiring a year of abstinence from gay and bisexual men was unrealistic and not supported by science.

"This new policy cannot be justified in light of current scientific research and updated blood screening technology," said David Stacy of Human Rights Campaign, the largest U.S. gay rights group.

Other activists said the new proposal would continue to stigmatize gay and bisexual men.

"This new policy does not require heterosexual blood donors to be celibate for one year. Some may believe this is a step forward, but in reality, requiring celibacy for a year is a de facto lifetime ban," Gay Men's Health Crisis, a New York-based nonprofit that supports AIDS prevention and care, said after the announcement.

The FDA's announcement follows years of government discussions re-examining the ban. Last month a panel of blood safety experts convened by the Department of Health and Human Services voted 16-2 in favor of doing away with the total ban. The panel recommended moving to the one-year ban that was formally proposed Tuesday.

The FDA implemented the lifetime ban in 1983, when health officials were first recognizing the risk of contracting AIDS via blood transfusions. Under the policy, blood donations are barred from any man who has had sex with another man at any time since 1977 — the start of the AIDS epidemic in the U.S.

The push for a new policy gained momentum in 2006, when the Red Cross, the American Association of Blood Banks, and America's Blood Centers called the ban "medically and scientifically unwarranted." Last year the American Medical Association voted to oppose the policy.

Patient groups that rely on a safe blood supply, including the National Hemophilia Foundation, have also voiced support for dropping the ban.