US President George W Bush has used his first veto during his six year presidency to reject a legislation that would have eased federal funding for stem cell research, saying the bill crosses a "moral" boundary.
"This bill crosses a moral boundary that our society needs to respect, so I vetoed it," Bush said on Wednesday.
He was addressing a gathering at the White House attended by families who had "adopted" frozen embryos that were not used by other couples, and then used those leftover embryos to have children.
"Each of these children was still adopted while still an embryo and has been blessed with a chance to grow, to grow up in a loving family. These boys and girls are not spare parts," Bush said.
The veto came a day after the Senate voted 63 to 37 to approve the legislation, but four votes short of the two third margin needed for overriding.
Numbers being what they are in the Senate and in the House of Representatives, it is highly unlikely that the presidential veto is going to be over-ridden.