23 December 2014 Last updated at 19:26 GMT
Gay and bisexual men should no longer be banned from donating blood in the US, the Food and Drug Administration (FDA) has recommended.
The ban has been in place since the HIV/Aids epidemic in the mid-1980s.
Men who have had sex with other men in the previous 12 months will still be banned, the FDA said in a statement.
The move brings the US into line with other countries such as the UK, Australia and Spain, which have also lifted outright bans in recent years.
New guidelines will be drafted in early 2015 and then a consultation period will follow.
Currently the ban excludes men who have had sex with other men at any time since 1977.
Campaigners have long argued the ban discriminates against gay and bisexual men and reinforces negative stereotypes.
And due to advances in HIV testing, the American Medical Association and other groups say the lifetime ban is no longer supported by science.
Blood donation around the world:
UK (excluding Northern Ireland), Japan and Australia have a one-year ban on men who have had sex with another man
Canada has a five-year ban
No ban in Italy, Mexico, Poland, Portugal, Russia and Spain, but some of those countries have tougher screening questions
Why are blood donors asked their sexual history?
"Over the past several years, in collaboration with other government agencies, the FDA has carefully examined and considered the available scientific evidence relevant to its blood donor deferral policy," the statement said.
It added: "The agency will take the necessary steps to recommend a change to the blood donor deferral period for men who have sex with men from indefinite deferral to one year since the last sexual contact."
The 12-month deferral period is because it takes on average two to four weeks to pick up an HIV infection when testing blood and a couple of months to detect Hepatitis B.
But some activists are unhappy there are still any restrictions.
"While this proposed change is certainly historic, it would still mean that countless gay and bisexual men will be turned away from blood banks simply because of who they are," said the Gay and Lesbian Alliance Against Defamation.
Men and women of any sexual orientation are not permitted to give blood for one year after having sex with someone with HIV, with a prostitute or with an intravenous drug user.