The American Medical Association on Tuesday endorsed cloning for research, saying it is medically ethical but allowing doctors who oppose the practice to refuse to perform it.
Policymaking delegates adopted the measure without debate after discussing the issue on Sunday.
"It makes a stance for science," said Dr Michael Goldrich, incoming chairman of the committee that drafted the cloning report.
The proposal focussed on a laboratory procedure designed to create embryos to cultivate their stem cells, which are master cells that can potentially grow into any type of human tissue.
Such embryos would be discarded when they consist of only a few cells, but they could theoretically develop into a human if implanted into a woman's uterus.
The AMA's Council on Ethical and Judicial Affairs submitted the proposal with hopes that it would become official AMA policy.