U.S. Senate Majority Leader Bill Frist said he will support legislation to remove some of the limitations on embryonic stem cell research.
Frist, a Republican who last month said he did not support expanded federal financing of such research, said his decision was consistent with both his experience as a physician and his opposition to abortion.
"Now is the time to expand the president's policy because it's promising research, but it must be done in a way that is ethically considerate, that respects the dignity of human life," said Frist, who also is a heart and lung transplant surgeon.
Frist, who has been said to be eyeing a run for the Republican presidential nomination in 2008, said only stem cells from embryos that "would otherwise be discarded," not implanted in a woman or frozen indefinitely, should be considered for research.
Interviewed on ABC television, Frist said his decision was based on policy, not politics.
Almost two-thirds of Americans say they support embryonic stem cell research and a majority of people say they would like to see fewer restrictions on taxpayer funding for those studies, according to recent polls.
"From those cells we have the potential for looking at those diseases that everybody knows about, Parkinson's, Alzheimer's and others," Frist said.
The senator planned to further outline his policy in a speech on the Senate floor later Friday.
Frist credited Bush with opening the doors for federal funding of embryonic stem cell research, and said when this policy was announced in 2001, policy-makers thought 78 stem cell lines would be available. Since then, the number has dropped to 22.
"Those 22 cell lines are not of the quality for human application or human therapy, and that's why today I believe we need to modify that policy," Frist said.
When Bush announced his position on stem cell research, he said the government should pay only for research of stem cell colonies, or lines, that had already been created at that time, so that the "life or death" decision had already been made, the AP reports.