Associated Press Writer

WASHINGTON (AP) -- President Bush called on the Senate Wednesday to pass legislation that would outlaw the cloning of human beings, technology that could be used in research and treatment of diseases.

"Life is creation, not a commodity," Bush said in a speech to 175 doctors, scientists, lawmakers, religious activists and disabled people.

"Advances in new biotechnology must never come at the expense of human conscience," he said. "As we seek what is possible, we must always ask what is right, and we must not forget that even the most noble ends do not justify any means."

Bush spoke up in order to urge the Senate to pass a broad ban on cloning, including the cloning of embryos for research.

The House in July passed a ban on all human cloning -- the production of embryos that are the genetic twin of a donor. Many in the Senate oppose using cloning to create human beings, but support using the process to create embryonic stem cells that may be used for research and the potential treatment of many diseases.

The bill Bush favors bans all human cloning, including cloning human embryos for research.

"It would be a mistake for the U.S. Senate to allow any kind of human cloning to come out of that chamber," Bush said.

Anything short of a full ban is unethical, Bush said, and would be nearly impossible to enforce. Moreover, the success of research that could stem from cloning is "highly speculative."

Most Americans oppose cloning, said Bush, whose conservative base favors a ban.

The cloning legislation joins a growing pile of bills that Bush favors and that have passed the Republican-controlled House but stalled in the Democratic-controlled Senate.

In recent days Bush has stepped up calls for action on an array of bills pending in the Senate, including measures that would increase energy conservation and exploration, grant him expanded powers in negotiating trade pacts and help businesses get terrorism insurance.

The use of embryonic stem cells is controversial because extracting the cells kills a living human embryo. Bush decided in August that federal funding would be permitted only for stem cell cultures that then existed and were made from embryos that were to be discarded by fertility clinics.

Sen. Bill Frist, R-Tenn., said Tuesday he would support the cloning ban, which the Senate is expected to debate in the weeks ahead. Though not a surprise, the announcement from Frist, a heart-transplant surgeon, is important because his views on medical topics are respected by many in Congress.

Creating a human embryo "for reason of experimentation leads to destruction of that embryo and to me that is morally unacceptable," Frist told reporters.

"I'm an advocate for embryonic stem cell research and stem cell research -- tremendous promise for Alzheimer's, Parkinson's, for the various diseases," he said Wednesday on CBS' "The Early Show." "But that is not the cloning of human embryos. I'm for cellular cloning, RNA cloning, DNA cloning, but not for cloning of embryos that have to be destroyed"

Bush holds a similar view and welcomed Frist's support, the White House said.

Sen. Sam Brownback, R-Kan., told an anti-cloning rally on Capitol Hill Wednesday that a ban on human embryo cloning was "clearly a winnable issue." Standing before a stack of petitions with 400,000 signatures for a cloning ban, Brownback said that "cloning is wrong, period. Creating human life to destroy it is wrong."

The cloning debate gained impetus in November when a Massachusetts company, Advanced Cell Technology, said it had cloned a human embryo for the first time. The company wants to extract stem cells from cloned embryos that could be used to grow healthy organs for patients.

Scientists also are trying to see whether adult stem cells can serve as all-around repairmen in the body, thus avoiding killing embryos.

The public overwhelmingly opposes scientific experimentation on the cloning of human beings, according to a new poll that also suggests public opinion is mixed on stem cell research.

Nearly four out of five people opposed cloning, while one-third of those polled were against federal funding of stem cell research, according to the poll by the Pew Research Center for the People & the Press.

The poll of 2,002 adults was taken Feb. 25-March 10 and had an error margin of plus or minus 2.5 percentage points.

Also Wednesday, Bush was mending fences with Bill Simon, the California Republican gubernatorial candidate whom the White House quietly opposed last fall. Simon was getting the royal treatment from the Bush administration, also meeting with Vice President Dick Cheney and a battery of Cabinet officials.