"We're going to be doing something on that soon, I think. The president is considering that right now," Obama adviser David Axelrod said on "Fox News Sunday."

In 2001, Bush limited federal funding for stem cell research only to human embryonic stem cell lines that already existed. It was a gesture to his conservative Christian supporters who regard embryonic stem cell research as destroying potential life, because the cells must be extracted from human embryos.

Embryonic stem cells are the most basic human cells which can develop into any type of cell in the body.

Scientists believe the research could eventually produce cures for a variety of diseases, including Parkinson's disease, diabetes, heart disease and spinal cord injuries.

Obama vowed to reverse Bush's ban during his presidential campaign and in his inaugural address last month promised to return science to its proper place in the United States.

The US Food and Drug Administration last month cleared the way for the first trial to see if human embryonic stem cells could treat people safely.

The trial will try to use stem cells from already existing lines to regrow nerve tissue in patients with crushed spinal cords.