US President Barack Obama signed an order yesterday that allows federal taxpayer dollars to fund expanded embryonic stem cell research, reversing one of his predecessor's policies viewed by many as blocking development of potentially life-saving medical treatment.

The executive order undoes former president George W. Bush's directive that was based on his determination that using embryos to create additional stem cell lines was morally wrong and, therefore, research on those lines should not be funded by the government.

Obama, however, said he was ending what he believed was "a false choice between sound science and moral values."