KAMPALA, Uganda -- President Yoweri Museveni of Uganda plans to sign a bill into law that prescribes life imprisonment for "aggravated" homosexual acts, officials said Friday.

Museveni announced his decision to governing party lawmakers, said government spokesman Ofwono Opondo. In Twitter posts on Friday, Opondo said the legislators, who are holding a retreat chaired by Museveni, "welcomed the development as a measure to protect Ugandans from social deviants."

Evelyn Anite, a spokeswoman for the governing party, said Museveni promised to sign the bill after he reads a report he has received from Ugandan "medical experts" saying "homosexuality is not genetic but a social behavior."

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Both officials said no date has been set for the signing.

Homosexuality already is criminalized in Uganda under a colonial-era law that criminalizes sex acts "against the order of nature."

Museveni has criticized gays as "abnormal" people who should be "rehabilitated." But he had previously said he opposed the legislation that Parliament passed on Dec. 20.

The bill would allow life imprisonment for acts of "aggravated homosexuality," defined as homosexual acts where one of the partners is infected with HIV, sex with minors or the disabled, and repeated sexual offenses among consenting adults. The bill also would make conducting a same-sex marriage ceremony punishable by seven years in prison.

Museveni has been under pressure within his own party to sign the bill since its passage.

Rights groups, including Amnesty International, have urged Museveni to reject the bill, which is popular among Christian clerics and lawmakers who say is necessary to deter Western homosexuals from "recruiting" children in Uganda.

On Friday, the organization Human Rights First expressed "deep concern" over the reports that the bill will be signed into law, saying it "will have severely adverse consequences for the human rights of lesbian, gay, bisexual, and transgender (LGBT) people as well as other Ugandans.'"

Robyn Lieberman of Human Rights First said, "There should be no doubt that Museveni's latest words on the subject have been influenced by the reaction to similar legislation in Nigeria, Russia and elsewhere."

Human Rights Campaign President Chad Griffin said, "Unless this bill is stopped from becoming law, lives will be destroyed and countless people will be punished for an immutable characteristic."

He said, "Anti-LGBT Americans advocated for laws further criminalizing LGBT people in Uganda, and it looks like they are now getting their wish. Whether it's Brian Brown advocating for anti-LGBT laws in Russia or Scott Lively calling for the further criminalization of LGBT people in Uganda, anti-LGBT Americans must stop exporting their hate abroad."