The U.N. General Assembly is planning to take up a controversial proposal later this month that could result in a ban on all human cloning. The United States is among 61 countries co-sponsoring the measure. A coalition of 125 scientific and patients' groups is spearheading opposition to the proposed ban.

A group calling itself the Coalition of the Advancement of Medical Research came to U.N. headquarters this week asking decision-makers to reject a global ban on therapeutic stem cell research.

All 191 U.N. member-states agree that reproductive cloning should be outlawed. That is cloning to produce babies.

But the consensus falls apart when it comes to the procedure known as therapeutic cloning. That is the creation of human embryos to provide stem cells for use in scientific studies.

Proponents call therapeutic cloning critical to the advancement of medical research.

South Korean researcher Woo Suk Hwang was the first to clone a human embryo and take stem cells from it. He told a U.N. news conference such cells provide the groundwork for a promising future in the treatment of previously untreatable degenerative conditions.

"It would be an incredible setback to science and medicine if we are stopped short of our goal here," he said. "Cloning holds so much hope and promise for the millions suffering from degenerative diseases."

Opponents, however, describe therapeutic cloning as the immoral taking of human life, and question its research value.

Costa Rica's U.N. Ambassador Bruno Stagno, who is heading the effort to impose a global ban, calls the term "therapeutic cloning" a misnomer with no scientific basis.

"I think once people study the science and the latest breakthroughs and developments, people will come to understand that human cloning is in the extreme, worrisome," he noted.

U.N. diplomats have only half-jokingly referred to human cloning as the most contentious non-political issue facing the world body. But with the two main U.S. presidential candidates taking opposing positions, the question of cloning and stem cell research is taking on a highly charged political tone.

The General Assembly debate will examine two competing proposals beginning October 21, less than two weeks before the presidential election.

The Bush administration supports the Costa Rican move to draft a treaty banning all human cloning. About 59 others, many of them predominantly Catholic and Muslim countries, have signed on as co-sponsors of the measure.

A separate proposal drafted by Belgium and supported by 21 other mostly European countries would prohibit reproductive cloning. But it would permit cloning of human embryos for stem cell and other scientific research.

Addressing the U.N. news conference, Daniel Perry of the Coalition for the Advancement of Medical Research recalled the life of "Superman" actor Christopher Reeve who died this month. Mr. Reeve's career was cut short after his spinal cord was damaged in a horseback riding accident nine years ago.

Mr. Perry said the actor had become a champion for millions of accident victims and others suffering debilitating diseases, giving them hope that stem cells grown from cloned embryos might lead to cures.

"Every breath he took was a struggle," he recalled. "And yet his example lifted up the spirits and the hopes of tens of millions of people who face other afflictions, other serious illnesses including Parkinson's disease, and Alzheimer's, and cancer and traumatic brain injury, and HIV/AIDS? conditions that our medical scientists believe we may be able to address far more effectively if given the freedom to pursue answers from stem cell research and therapeutic cloning."

Costa Rica's Ambassador Stagno argued that scientists have failed to prove human cloning has any research value. In an interview with VOA, he said that important stem cell research would not be prohibited by the proposed cloning ban.

"Our position is firmly grounded in science," said Mr. Stagno. "We have asked them to provide us with any proof that they might have that human cloning has in any way led to positive results, they have not been able to provide positive results in animal cloning regarding most of the diseases they claim could be cured through cloning, so we don't understand why people want to move forward with human cloning when usually we have appropriate safeguards and we don't jump into human cloning until there is sufficient evidence of the tests done with animals."

The General Assembly is evenly divided on the issue. Last year, in a setback to the United States, members decided by a one vote margin to put off writing a cloning treaty for two years. That decision was later overturned to allow the matter to come up again this month.

Costa Rican and U.S. diplomats are hoping for a quick General Assembly vote that would clear the way for the treaty-drafting process to begin.

Opponents, however, are considering delay tactics that would postpone a decision until after the U.S. election. They calculate that if Democrat John Kerry wins there would likely be a change in U.S. policy, and a subsequent shift in the U.N. General Assembly debate.