Former US First Lady Nancy Reagan has urged the Bush administration to support embryonic stem cell research.
Ronald Reagan is suffering the advanced stages of Alzheimer's disease
Mrs Reagan said too much time had been wasted already discussing the issue.
She is said to believe the research could lead to a cure for Alzheimer's disease, which has afflicted her husband, Ronald Reagan.
The Bush administration has blocked public funding of this type of research because of his party's ethical reservations about embryo research.
At a fundraising dinner for the Juvenile Diabetes Research Foundation in Hollywood, Mrs Reagan said her husband was now in "a distant place where I can no
longer reach him".
"I just don't see how we can turn our backs on this... We have lost so much time already. I just really can't
bear to lose any more."
She said she believed stem cell research "may provide
our scientists with many answers that for so long have been beyond our grasp".
It is thought to be the first time that Mrs Reagan has made a public speech on the issue, although her views have long
Mrs Reagan is the latest high-profile figure to criticise the Bush administration for its decision to limit funding for stem cell research.
Former Superman actor Christopher Reeve, left severely disabled following a riding accident, and actor Michael J. Fox, who is suffering from Parkinson's disease, have both criticised the Bush administration for blocking research which they believe could improve their conditions.
Actor Michael J. Fox praised Mrs Reagan for "taking the issue out of politics"
Currently federal funds are not available for this type of work.
Mr Bush has told scientists he will not release US taxpayers' money for the production or investigation of new lines because it involves the destruction of human embryos.
Correspondents say that with the Bush administration and anti-abortion groups strongly opposed to stem cell research, Mrs Reagan's comments add a powerful conservative Republican voice to the debate.