In a landmark policy change that angered anti-abortion groups, Mr Obama signed an order to permit public money to be used for research that scientists hope will produce cures for a range of serious conditions such as Parkinson's.

“We will bring the change that so many scientists and researchers, doctors and innovators, patients and loved ones have hoped for, and fought for, these past eight years,” Mr Obama said at the White House.

Stressing that “medical miracles do not happen simply by accident”, the president said the government needed to support research to find cures for diseases such as diabetes and cancer. He also cast the move as an attempt to stem the flow of US scientists to overseas laboratories, avoiding a situation in which other countries “may surge ahead of ours in the advances that transform our lives”.