An influential US senator has proposed withholding aid to Uganda after the African nation's president signed a law imposing life prison sentences for homosexuals.
"I am deeply concerned by the decision of President (Yoweri) Museveni of Uganda to sign into law the anti-homosexuality bill," Senator Patrick Leahy, the most senior member of the chamber and chairman of the Senate Judiciary Committee, said in a statement.
"Much of US assistance to Uganda is for the people of Uganda, including those in the Ugandan LGBT (lesbian, gay, bisexual and transgender) community whose human rights are being so tragically violated.
"But we need to closely review all US assistance to Uganda, including through the World Bank and other multilateral organisations."
Washington is among Uganda's largest international donors. Congress has requested $US456.3 million ($A506.61 million) in aid to the impoverished nation, mostly for health programs, for 2014.
The State Department has signalled it is looking at a range of options to respond to the law, while White House spokesman Jay Carney said "we are undertaking a review of our relationship with Uganda in light of this decision".
Leahy chairs the appropriations subcommittee on State Department and foreign operations, and he has several options at his disposal, including inserting language in a 2015 aid bill that puts conditions on US assistance to Uganda.
Some lawmakers argued against cutting off aid.
"Africa is a continent in peril. The problems in Uganda with AIDS, and, you know, kids starving - do we deny economic aid to the developing world in Africa, which could be an ally, over an issue like this?" asked Republican Senator Lindsey Graham.
"I'm not so sure that's the right answer."

